Periodic Law Review

Chapter 5

• This man organized the periodic table by increasing atomic mass.

• This man organized the periodic table by increasing atomic number.

• The definition of periodic law is…

Dmitri Mendeleev

Henry Moseley

Physical and chemical properties are periodic functions of their atomic numbers.

• Periodic functions means….

• The name of the first family.

• The name of the second family.

A repeating trend because of..

Alkali metals

Alkaline Earth Metals

• The name of the 2nd to last family.

• The name of the last family.

• This family all ends in s2

Halogens

Noble Gases

Alkaline Earth Metals

• This family ends in p6

• This family ends in s1

• This family ends in p5

Noble Gases

Alkali Metals

Halogens

• These three families are highly reactive.

• This family is relatively unreactive.

• This family gains 1e- when bonding.

Alkali metals, halogens, and alkaline earth metals

Noble gases

halogens

• This family loses 1 e- when bonding.

• This family loses 2e- when bonding.

• This family has a full s and p orbital in the principal energy level.

Alkali metals

Alkaline earth metals

Noble gases

• The definition of electronegativity…

• The trend across a period….

• The trend down a family/group.

The measure of the tendency of an atom to gain an electron from another atom.

Electronegativity increases.

Electronegativity decrease or remain the same.

• The definition of electron affinity…

• The trend across a period….

• The trend down a family/group.

The energy change that occurs when an electron is acquired by a neutral atom.

Electron affinity become more negative in the p block; becomes more positive going from group 1 to group 2.

The energies become less.

• The definition of ionization energy…

• The trend across a period….

• The trend down a family/group.

The energy required to remove one electron from a neutral atom of an element.

Ionization energies of the main group elements increase across a period.

Ionization energies of the main group generally decrease down a group.

• The definition of atomic radius…

• The trend across a period….

• The trend down a family/group.

The average distance between two bonded atoms.

Atomic radius decreases across a group.

Atomic radius increases down a group.

• The definition of ionic radii…

• The trend across a period….

• The trend down a family/group.

The average distance between 2 bonded atoms that are a cation or anion.

Cationic radii decrease across a period. Anionic radii decrease across each period.

Ionic radii (cationic and anionic) increase down a group.

• The definition of valence electrons…

• The trend across a period….

• The trend down a family/group.

The number of electrons found in the outermost s and p orbitals. They are available to gain, lose or share.

Valence electrons increase by 1 in the main group.

Valence electrons remain the same in each family.

• H

• V

• C

Hydrogen

Vanadium

Carbon

• O

• S

• U

Oxygen

Sulfur

Uranium

• F

• I

• Ne

Fluorine

Iodine

Neon

• Br

• Mg

• Ca

Bromine

Magnesium

Calcium

• Pt

• Ti

• Sn

Platinum

Titanium

Tin

• W

• Au

• Hg

Tungsten

Gold

Mercury

• Rn

• Fr

• Ar

Radon

Francium

Argon

• Sc

• Be

• Li

Scandium

Beryllium

Lithium

• How many atoms are in 1 mol?

• What is the above number referred to as?

• The number of protons is called?

6.022 x 1023

Avogadro’s number

Atomic number

• The number of protons + neutrons is called?

• Atoms of the same element which differ in the number of neutrons are called?

• The average mass taking into account the abundance of all of the isotopes of that element is called?

Mass number

isotopes

Atomic mass (that’s why it is a decimal on the periodic table.

• How do you obtain the mass number when all you are given on the periodic table is atomic number and atomic mass?

• The element [He] 2s2

• The element [Kr] 5s1

Rounding the atomic mass to the nearest whole number will give you the mass number of the most common isotope.

Be

Rb

• The electron configuration for K.

• The electron configuration for C.

• The electron configuration for Kr.

1s22s22p63s23p64s1

1s22s22p2

1s22s22p63s23p64s23d104p6

• The noble gas configuration for P.

• The noble gas configuration for As.

• The noble gas configuration for Ne.

[Ne]3s23p3

[Ar]4s23d104p3

[He]2s22p6

• Convert 4 .0mol O to atoms of O.

• Convert 25.0 x 1023 atoms S to mol S.

• Convert 14.0 g Mg to mol Mg.

4.0 mol O x 6.022 x 1023 atoms =2.4 x 1024

1 mol O

25.0 x 10 23 atoms S x 1 mol =4.15 mol S

6.022 x 1023 atoms

14.0 g Mg x 1 mol Mg = .576 mol Mg

24.30 g Mg

• Convert 14.0 g of O to mol O.

• Convert 10.0 g of Au to atoms Au.

• Convert 5.0 g S to atoms of S.

14.0 g O x 1 mol =.875 mol O

16.0 g O

10.0 g Au x 6.022 x 1023 atoms Au =3.06 x 1022

196.97 g Au

5.0 g S x 6.022 x 10 23 atoms S = 9.4 x 10 22 atoms S

32.065 g S