Upload
leojohn2
View
228
Download
0
Embed Size (px)
DESCRIPTION
6th grade science intro to atoms and elements
Citation preview
Do NowWhy are some objects or liquids more dense than others?
Objective-Understanding Atoms
Properties of Matter
MatterYou need to
remember that all MATTER is made up of Atoms.
Matter has mass and takes up space
Particles of MatterAtoms – The smallest particle of an Element
that retains the chemical properties of that element
Democritus – 400 BC, a Greek philosopher that coined the term “atomos which means “uncuttable, indivisible”
AtomsAll solids, liquids and gases are made up of
ATOMSTo be able to understand a little more about
an ATOM think of a Drop of WaterScientist’s say in 1 drop of water, there are 6
sextillion atoms- 6x10^21 (6000000000000000000000)
Do NowPlease list the 4 parts that make up an atom
Objective: SWBAT- Understand the structure of an Atom
What makes up a Atom?Atoms are
composed of three types of particles-(i.e-parts )
NeutronsProtonsElectronsThe Neutrons and
Protons are found in the Nucleus (which is the heart of the Atom
NeutronsAre found in the
nucleus of an atomNeutrons have no
charge, They are Neutral
The number of Neutrons will vary
Don’t be tricked its not a negative charge, think
Neutron=Neutral
ProtonsThey are also found
in the Nucleus of an atom
Protons have a positive (+) charge
Way to remember THINK Proton=Positive
Electrons Electrons are found on the outside of the nucleus. They orbit around the nucleus.
They have a negative charge (-).
The mass of an electron is very small
The more electrons the more negative an atom, the less electrons the more positive an atoms is.
Do Now- Name the 3 parts of the atom and the charges each give off
Electrons-They have a negative charge (-). Neutrons- The have neutral Protons- Have a positive
SWBAT- Know the differences between compounds and molecules
John Dalton -1802 - The Atomic TheoryAtoms can not be broken into smaller pieces – atoms
are like a solid marble (Not entirely accurate)
Compounds are always composed of whole number proportions of elements ie CO2 – Carbon dioxide, H2O – Water, C6H12O6 – Glucose, NaCl – Table Salt (this one is true also)
The basic particle of an Element is the Atom – H, He, Fe, etcThe basic particle of a Compound is the Molecule – a group of atoms that are chemicallybonded and act as a single unit until the bonds are broken: CO2, H2O, C6H12O6, NaCl
REVIEWhttps://www.brainpop.com/science/matterand
chemistry/atoms/
CompoundsA Compound is a molecule that at least 2 different elements.
MoleculeA molecule is formed when two or more
atoms join together chemically. A compound is a molecule that contains at least two different elements.
All compounds are molecules but not all molecules are compounds.
CompoundsMolecular hydrogen (H2), molecular oxygen
(O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element.
Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element. The smallest bit of each of these substances would be referred to as a molecule.
An atom refresherAn atom has three
parts:Proton = positiveNeutron = no chargeElectron = negative
The proton & neutron are found in the center of the atom, a place called the nucleus.
The electrons orbit the nucleus.
Picture from http://education.jlab.org/qa/atom_model_03.gif
Do Now: Is this a compound or a molecule? Explain why He4 …….CH4
He4= Molecule- single elementCH4= Compound- 2 or more elements
SWBAT- Explain why elements are sometimes called the building blocks of matter
Isotope
Periodic Table
8
OOxygen
16
Atomic Number:Number of protons and it is also the number of electrons in an atom of an element.Element’s Symbol:An abbreviation for the element.Elements Name
Atomic Mass/Weight:Number of protons + neutrons.
Atom ModelsThere are two models of the atoms we will
see in class.Bohr ModelLewis Dot Structure
Bohr ModelThe Bohr Model shows all
of the particles in the atom.
In the center is circles. Each circle represents a single neutron or proton. Protons should have a plus or P written on them. Neutrons should be blank or have an N.
In a circle around the nucleus are the electrons. Electrons should have a minus sign or an e.
++
-
-
Electrons have special rules….You can’t just shove all of the electrons
into the first orbit of an electron.Electrons live in something called
shells or energy levels.Only so many can be in any certain
shell. The electrons in the outer most shell
of any element are called valance electrons.
Nucleus
1st shell
2nd shell
3rd shell
Adapted from http://www.sciencespot.net/Media/atomsfam.pdf
So let’s try it….
How to draw a Lithium atomFirst, look at the Periodic TableSecond, determine the number of
protons (Look @ the atomic number)
Then determine the number of neutrons (Atomic mass – atomic number)
Then determine the number of electrons (Look @ the atomic number)
3
LiLithium
7
So let’s try it….3
LiLithium
7
+++
Protons = 3
Neutrons = 4(7-3=4)
-
-
-
Electrons = 3 2 in the 1st shell, 1 in the 2nd shell
Lewis Dot StructureThe Lewis Dot
Structure is a bit different from the Bohr model.
It only shows the element symbol and it’s outer most electron shell.
O• ••• •
•
+ +
+ +
+
++
+
-
-
- -
--
- -
How to… 1. Write the
symbol.2. Start on the
right hand side, working your way clockwise around the symbol.
3. Try Lithium