Name: Atoms & The Periodic Tableawarscience.weebly.com/.../unit_6_atoms_guided_notes.pdf• The periodic table displays each _____ in a box. In most periodic tables, each box In most

© Stephanie Elkowitz

Name: ____________________________

Atoms & The Periodic Table

WHAT IS AN ATOM?

• What is an atom?

• ______________________________________________________________________________

______________________________________________________________________________

• All ______________ are made of atoms. The ______________, your ______________ and

even ______________ ______________ are made of atoms.

• Atoms are ______________ ______________. One atom is only one ______________ of a

meter wide!

DEMOCRITIS

• The idea of an atom was first developed around ______________ by Greek philosopher

______________. Democritus believed that you could not ______________ break an object

in half. At some point, you get to the ______________ bit of matter, which cannot be broken.

He called this bit of matter an ______________.

JOHN DALTON

• In ______________, English chemist John ______________ proposed and published his

theory on atoms. Dalton believed ______________ was made of extremely small

______________. Atoms of the same substance have identical ______________,

______________ and other properties. Dalton also believed atoms could not be

______________, ______________ or ______________ but could combine to form different

chemical substances.

J.J. THOMSON

• In ______________, English physicist J.J. ______________ discovered the ______________.

Thomson discovered that an electron is a tiny, ______________ charged particle. From this

finding, Thomson proposed the first ______________ of an atom.

• Thomson came up with his model of the atom in ______________. According to Thomson, an

atom was made of ______________ charged particles (______________) embedded in a

“soup” of ______________ charges.

• Why was Thomson’s atomic model called the plum pudding model?

• ______________________________________________________________________________

______________________________________________________________________________

• Draw a picture of Thomson’s plum pudding model.

ERNEST RUTHERFORD

• Ernest ______________ proposed an alternative model in ______________. According to

Rutherford, an atom is made of a central, ______________ charged region. He called this

region the ______________. Rutherford believed electrons surrounding the nucleus as a

“______________.” He also believed the nucleus of the atom was ______________ and

______________ compared to the overall size of the atom.


• Draw a picture of Rutherford’s atomic model.

• Rutherford proved his model of the atom with a famous experiment known as the

______________ ______________ experiment.

• Who did Rutherford work with on this experiment?

1. ___________________________

2. ___________________________

• In this experiment, Rutherford shot a beam of ______________ charged particles, called

______________ particles, at a thin piece of ______________ foil. He recorded where the

alpha particles ______________ as they struck the gold foil.

• What should have happened if Thomson’s model was correct?

• ______________________________________________________________________________

______________________________________________________________________________

• What did Rutherford actually observe during this experiment?

• ______________________________________________________________________________

______________________________________________________________________________

• Rutherford believed his model explained these results:

1. Most particles ______________ through because an atom is mostly ______________

______________.

2. Some particles ______________ because they were deflected by negatively charged

______________.

3. Some particles ______________ back because they bounced off the positively

charged ______________.

NEILS BOHR

• In 1914, Neils ______________ modified Rutherford’s model of the atom. Like Rutherford,

Bohr believed an atom is made of a small, ______________ charged nucleus surrounded by

______________ charged electrons.

• How was Bohr’s atomic model different from Rutherford’s?

______________________________________________________________________________

______________________________________________________________________________

• Draw a picture of the Rutherford-Bohr atomic model.


ATOMIC STRUCTURE

• According to this model, there are 2 major regions of an atom:

1. ___________________________________________________________________________

2. ___________________________________________________________________________

• Atoms are VERY tiny! There are so small, that we use special units of ______________ to

describe the ______________ and ______________ of atoms and particles within atoms.

• We measure the mass of atoms and the particles with an atom in ______________

______________ units (u). One atomic mass unit equals ______________ kilograms.

• We measure the size of atoms in ______________ (pm). One picometer equals one

______________ of a meter. In other words, 1 picometer equals ______________ meters. An

atom is approximately ____ pm wide.

• ______________ particles are the particles found within an atom. They are:

1. ___________________________

2. ___________________________

3. ___________________________

• Describe each subatomic particle in the table below.

Particle Location Charge Mass

Proton

Neutron

Electron

• Label the subatomic particles in the atom below.

• Because the nucleus contains ______________ and ______________ particles, the net

charge of the nucleus is ______________. A force known as the ______________ force holds

the proton(s) and neutron(s) together in the ______________.

• The space around the nucleus is ______________ charged because it contains negatively

charged ______________. ______________ stay in orbit around the nucleus due to

______________ force. This force “______________” an atom together.

• Although we cannot view the arrangement of ______________ particles within an atom, we

have an instrument that allows us to see the ______________ of atoms. A ______________

______________ microscope (STM) can view the atoms on the surface of an object.


ELEMENTS

• All atoms have the same ______________ of subatomic particles. A change in the

______________ of subatomic particles will change the ______________ of atom.

• An ______________ is a type of atom with the same number of ______________. We also

use the term element to describe a ______________ that is made of the same type of atom.

• An element is often abbreviated with a one of two letter ______________.

• Complete the tables below to show the symbol for several common and important elements.

Element Symbol Element Symbol

Hydrogen Neon

C Helium

Oxygen F

Nitrogen Cl

Na Aluminum

Li Fe

ELECTRON SHELLS

• Electrons constantly move around the ______________ of an atom. They orbit the nucleus in

specific ______________ or ______________ that surround the nucleus. A shell is also called

an ______________ ______________. It called so because a shell is associated with a

certain amount of ______________.

• The shell closest to the nucleus has the ______________ energy. ______________ in this

shell have the least amount of energy. As you move away from the nucleus, the

______________ associated with a shell ______________. Electrons in the shell furthest

away from the nucleus have the ______________ energy.

• Each shell can only hold so many ______________:

- The first shell can hold ______________ electrons.

- The second shell can hold ______________ electrons.

- The third shell can hold ______________ electrons.

- The fourth shell can hold ______________ electrons.

• In large atoms, you can find up to ______________ shells. No shell can hold more than

______________ electrons.

ELECTRON CONFIGURATION

• How electrons are arranged in the shells of an atom is called ______________

______________. Electrons “fill” or take up ______________ in each shell.

• In general, electrons fill ______________ shells first because lower shells have

______________ energy. Once a shell is full, electrons begin to fill the next ______________

shell.

BOHR DIAGRAM

• To show electron configuration, we draw a diagram called a ______________ Diagram. To

draw a Bohr Diagram:

1. Draw a ______________ to represent the nucleus of an atom.


2. Write the ______________ of the element, the number of ______________ and

number of ______________ inside the circle.

3. Draw ______________ around the circle to represent electron shells.

4. Draw electrons as ______________ on the rings. Remember, each “ring” can only

hold so many electrons.

• Draw a Bohr diagram of Carbon, which has 6 protons, 6 neutrons and 6 electrons.

• Draw a Bohr diagram of Sodium, which has 11 protons, 12 neutrons and 11 electrons.

VALENCE ELECTRONS

• The electrons found in the outermost orbital are called ______________ electrons. For this

reason, the outermost shell is also called the ______________ shell. The number of

______________ electrons determines many chemical ______________ of an element.

• An atom cannot have more than ______________ valance electrons. An atom with

______________ valance electrons is said to have a ______________ outer shell. For

example, ______________ has 8 valance electrons.

• Helium has a full valance shell with only ______________ electrons. Helium only has one

shell. The maximum amount of electrons held in the first shell is ______________ electrons.

Since the shell holds the maximum amount of ______________ it can hold, Helium is said to

have a ______________ valance shell.

ATOMIC NUMBER & MASS

• There are two important numbers associated with an element that help you determine the

number of protons, neutrons and electrons in a neutral atom of that element:

1. ___________________________

2. ___________________________


ATOMIC NUMBER

• What is atomic number?

• ______________________________________________________________________________

______________________________________________________________________________

• Atoms of the same ______________ have the same number of ______________ and thus,

the same ______________ number.

ATOMIC MASS

• Atomic mass is the ______________ of an atom. Atomic mass is measured in

______________ ______________ ______________.

• Atomic mass equals the sum of ______________ and ______________ in an atom.

Remember, the mass of a proton is ______________ and the mass of a neutron is

______________.

• Why do electrons not contribute to the mass of an atom?

______________________________________________________________________________

______________________________________________________________________________

• Example: Carbon has 6 protons and 6 neutrons. What is carbon’s atomic mass?

• If you know an atom’s ______________ number and the number of ______________, you

can calculate atomic mass.

• Write the equation to calculate atomic mass:

• ______________ + ______________ = ______________

• If you know an atom’s atomic mass and atomic number, you can calculate the number of

______________ in an atom.

• Write the equation to calculate number of neutrons:

• ______________ − ______________ = ______________

• Example: Nitrogen has an atomic mass of 14. Its atomic number is 7. How many neutrons

are found in this atom?

ATOMIC VARIATIONS

• The number of ______________ is the same for all atoms of a specific ______________.

• A change in the number of ______________ will change the ______________ of atom – the

______________ to which the atom belongs.

• The number of neutrons and electrons in an atom can ______________ without changing

the ______________ to which the atom belongs.

• A change in the number of ______________ will change the ______________ of an atom.

Different forms of atoms are called ______________.

• The change in the number of ______________ will change the ______________

______________ of an atom. Atoms with electric charge are called ______________.


ISOTOPE

• An ______________ is a variety of an element with a different number of neutrons. The

name of an isotope is the name of the element followed by a dash (_____) and the atomic

______________ of the isotope.

• Carbon has 6 protons. How would you write the name of:

1. Carbon with 6 neutrons? ______________________



AVERGE ATOMIC MASS

• What is average atomic mass?

______________________________________________________________________________

______________________________________________________________________________

• To find average atomic mass:

1. Identify the different ______________ of the element and the atomic

______________ of each isotope.

2. Multiply the atomic mass of each ______________ by its ______________

______________ (in decimal form). Percent ______________ is the percent the

element is found in the ______________ ______________.

3. Find the ______________ of these values. The sum is equal to ______________

atomic mass.

• Example: Chlorine

• Average atomic mass gives you an idea as to what the most common ______________ of an

element is. To find the most common ______________, round ______________ atomic mass

to the nearest whole number. This “trick” works for most elements.

RADIOACTIVE ISOTOPE

• Most isotopes are ______________. Stable isotopes have a “happy” ______________ of

protons and neutrons.

• Some isotopes are not ______________. An unstable isotope is called a ______________

isotope. A radioactive isotope is called so because it emits ______________.

• What is radiation?

• ______________________________________________________________________________

______________________________________________________________________________

• Why is radiation dangerous?

• ______________________________________________________________________________

______________________________________________________________________________

RADIOACTIVE DECAY

• A radioactive isotope releases ______________ in order to become ______________. This

process is called ______________ ______________.

• During ______________ decay, the atom emits ______________. ______________ can be

high-energy ______________ and/or ______________ particles.


• As the atom undergoes radioactive decay, it becomes ______________. As a stable isotope,

the atom no longer emits ______________.

ION

• An element can gain or lose ______________ to form an ______________. An ion is an atom

with an ______________ charge.

• Neutral atoms have the same amount of ______________ and ______________. These

atoms have zero net charge. An ion does not have the ______________ amount of protons

and electrons. These atoms have a ______________ or ______________ charge.

• When an atom loses an electron, it loses a ______________ charge. Therefore, the atom has

more protons and is ______________. A positive ion is called a ______________.

• Complete the diagram to show an atom losing an electron.

• When an atom gains an electron, it gains a ______________ charge. Therefore, the atom

has more electrons and is ______________. A negative ion is called an ______________.

• Complete the diagram to show an atom losing an electron.

• To determine the electric charge of an ion, you must know the ______________ between

protons and electrons.

• If there are more ______________, the ion is ______________. A “____” is used to denote s

positive ion. If there are more ______________, the ion is ______________. A “____” is used

to denote a negative ion.

• Write the charge as a ______________ to the right of the atom. If the ion has a +1 charge,

simply write ____. If the ion has a -1 charge, simply write ____.

• Example: A sodium atom has 11 protons and 10 electrons. How do you denote the charge

on this atom?

• Example: An oxygen atom has 8 protons and 10 electrons. How do you denote the charge on

this atom?


• An atom wants to gain or lose electrons in order to have a complete ______________ shell.

• An atom that has only one or two valance electrons tends to ______________ those

electrons and become a ______________ ion.

• What happens to lithium and why?

______________________________________________________________________________

______________________________________________________________________________

• An atom that has nearly a full valance shell tends to ______________ electrons and become

a ______________ ion.

• What happens to fluorine and why?

______________________________________________________________________________

______________________________________________________________________________

PERIODIC TABLE

• There are more than 100 different ______________. All the known elements are organized

in a table. This table is called the ______________ ______________ of ______________.

• The periodic table displays each ______________ in a box. In most periodic tables, each box

gives 4 pieces of information about the elements:

1. _________________________

2. _________________________

3. _________________________

4. ________________________

• Elements are presented in the periodic table by order of ______________ atomic

______________.

• Elements are arranged in rows and columns in the periodic table. The rows are called

______________. The columns are called ______________.

• ______________ ______________ dictates how elements are organized in the rows and

columns of the periodic table. Elements with the same number of ______________ electrons

are placed in the same column. Elements with the same number of ______________ are

placed in the same row.

• This organization explains the ______________ of the periodic table.

• There are four major types of elements in the periodic table:

1. _________________________

2. _________________________

3. _________________________

4. _________________________

• Outline and label the major types of elements in the table.


METALS

• Most elements are ______________.

• What are characteristics of metals?

______________________________________________________________________________

______________________________________________________________________________

• What are some examples of metals?

______________________________________________________________________________

______________________________________________________________________________

NONMETALS

• ______________ make up the majority of the universe.

• What are characteristics of nonmetals?

______________________________________________________________________________

______________________________________________________________________________

• What are some examples of nonmetals?

______________________________________________________________________________

______________________________________________________________________________

• Hydrogen is a ______________ even though it is located on the periodic table where most of

the metals are found.

METALLOIDS

• ______________ have characteristics in-between metals and nonmetals.

• Metalloids are ______________ and have a “______________ appearance.” Although they

look like metals, most metalloids are ______________, not ______________ and fair

______________.

• What are the 6 commonly recognized metalloids?

1. _________________________

2. _________________________


3. _________________________

4. _________________________

5. _________________________

6. _________________________

• ______________ and/or ______________ are sometimes included.

NOBEL GASES

• ______________ and ______________ are sometimes included as metalloids.

• Nobel gases are ______________, ______________ elements. As their name suggests,

Nobel gases are ______________ at room temperature.

• Nobel gases are ______________ conductors.

• What are the 6 Nobel gases?

1. _________________________

2. _________________________

3. _________________________

4. _________________________

5. _________________________

6. _________________________

PERIODIC TABLE GROUPS

• Recall: Elements in the same group have the same number of ______________ electrons.

• The number of valance electrons is easy to determine for groups 1, 2 and 13 through 18.

Elements in group 1 have ____ valance electron, elements in group 2 have ____ valance

electrons and so on.

• There are ______________ to this pattern in the center block of elements and to the rows of

elements below the table. These elements are called ______________ metals.

• Transitional metals have ______________ electron configuration. Electrons are added to the

______________ to last orbital instead of the ______________ shell.

• Some groups have specific names because they share similar properties:

1. _________________________

2. _________________________

3. _________________________

4. _________________________

5. _________________________

• Elements in these groups share similar ______________ because they have the same

number of ______________ electrons.

• Outline and label the periodic table groups in the periodic table below.


• Describe each of the groups in the table below.

Group Characteristics

Alkali Metals

Alkaline Earth

Metals

Transitional

Metals

Halogens

Nobel Gases

F BLOCK ELEMENTS


• Below the period table are two rows of elements. These rows make up the ______________

of the periodic table. Elements in the F block are ______________ of the periodic table, but

it’s easier to ______________ them on the bottom of the table.

• Each row is considered a ______________ of elements. The first row is called the

______________ series. The second row is called the ______________ series.

LATHANIDE SERIES

• The lanthanide series includes chemical elements with atomic numbers ____ through ____.

All of these elements are shiny, ______________ ______________. These elements are

______________.

• What are some uses for Lanthanide elements?

______________________________________________________________________________

______________________________________________________________________________

ACTINIDE SERIES

• The actinide series include chemical elements with atomic numbers ____ through ____. All

of these elements are ______________.

• Some of the actinide elements are ______________ - they are not found nature. Elements

with atomic numbers ______ through ______ are synthetic elements.

• What are some uses for Actinide elements?

______________________________________________________________________________

______________________________________________________________________________

SYNTHETIC ELEMENTS

• There are other ______________ elements in the periodic table. In total, there are ____

synthetic elements. These elements have atomic numbers ____ through ____. Synthetic

elements do not occur ______________ on Earth. All synthetic elements were made in a

______________.

• All synthetic elements are ______________ and ______________. They decay

______________, some in only a few hundred ______________.

• Some elements, such as ______________ and ______________, are synthetically made.

However, they are not purely synthetic. They exist ______________ in very minute quantities

on Earth.

PERIODIC TABLE TRENDS

• There are patterns to the properties of elements in the periodic table. These patterns are

called ______________.

ATOMIC RADIUS

• What is atomic radius?

______________________________________________________________________________

______________________________________________________________________________

• How does atomic radius change as you move down a column?

______________________________________________________________________________

______________________________________________________________________________

• How does atomic radius change as you move across a row?

______________________________________________________________________________

______________________________________________________________________________

ELECTRONEGATIVITY


• What is electronegativity?

______________________________________________________________________________

______________________________________________________________________________

• How does electronegativity change as you move across a row?

______________________________________________________________________________

______________________________________________________________________________

• How does electronegativity change as you move up a column?

• ______________________________________________________________________________

______________________________________________________________________________

IONIZATION ENERGY

• What is ionization energy?

______________________________________________________________________________

______________________________________________________________________________

• How does ionization energy change as you move across a row?

______________________________________________________________________________

______________________________________________________________________________

• How does ionization energy change as you move up a column?

• ______________________________________________________________________________

______________________________________________________________________________

METALLIC CHARACTER

• Elements, except ______________, on the left side of the periodic table are

______________. These elements have ______________ character.

• ______________ character refers to characteristics of metals.

• What are 4 characteristics of metals?

1. _________________________

2. _________________________

3. _________________________

4. _________________________

• Metalloids have some ______________ character. Nonmetals do not have ______________

character, which is why they are called nonmetals.

• How does metallic character change as you move across the periodic table?

• ______________________________________________________________________________

______________________________________________________________________________

• Summarize the periodic table trends on the table below


.

Reflection Questions

1. Summarize how the model of an atom changed over the years.

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

2. What are the similarities and differences between a proton, neutron and electron?

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

3. What happens when the amount of protons, neutrons or electrons change in an atom?

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

4. Summarize some of the important trends of the periodic table of elements.

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

Documents

Name: Atoms & The Periodic Tableawarscience.weebly.com/.../unit_6_atoms_guided_notes.pdf• The periodic table displays each _____ in a box. In most periodic tables, each box In most