The Periodic Table

Twelve elements have been known since ancient times.

What do you think they are?

(Name them, use your periodic table to help you.)

The Periodic Table

Twelve elements have been known since ancient times.

What do you think they are?

(Name them, use your periodic table to help you.)

carbon, sulfur, iron, copper, arsenic, silver, tin, antimony, gold, mercury, lead, bismuth

The Periodic Table

Why do you think these particular elements have been known for so long, while most elements were not discovered until the 1800s and 1900s?

Overview of the Periodic Table

Metals Metalloids Nonmetals Noble gases

Overview of the Periodic Table

Metals Metalloids Nonmetals Noble gases

1. excellent heat conductor2. excellent electrical conductor3. lustrous (shiny)4. malleable, ductile5. silvery-gray, except Cu and Au6. solids at room T, except Hg

Some properties of metals, some properties of nonmetals1. moderate electrical conductivity2. appearance – more like metals – lustrous, silvery-gray3. brittle like nonmetals4. solids at room T

1. poor heat conductors

2. poor electrical conductors

3. not lustrous4. brittle5. variety of

colors6. gases or brittle

solids at room T

1. extremely unreactive – “inert”

2. rarely form compounds with other elements

3. colorless, odorless gases at room T

Trends of the Periodic Table “periodic” = repeating pattern

Overall theme = electrons’ positions relative to each other and the nucleus determine the following properties:

4. Electron configuration

5. Ionic radius

Electron Configuration

Compare the charges on the ion list with the positionof the element in the periodic table

Electron Configuration

• Noble gas configuration = [core] e-’s

• ‘Outer’ electrons = valence e-’s

• Elements of groups 1A-8A have valence e-’s in s and p orbitals

Periodic Trends

The position of a valence electron and the ability to remove it from an atom are related to

• the number of protons in the nucleus

• the extent to which the valence electron is shielded from the positively-charged nucleus by the negatively-charged core electrons

Isoelectronic Series

= a group of ions and atoms that have the same electron configuration

1. Draw the electron configuration of each of the following elements.

2. What ions will they form?

3. When ions, how many electrons does each have? How many protons?

4. Predict the relative diameters of the members of this isoelectronic

series.

Isoelectronic Series

Element Electron config

Ion Ion # e-’s

Ion # p+

O

F

Ne

Na

Mg

Prediction: smallest to largest:

Isoelectronic Series

Element Electron config

Ion Ion # e-’s

Ion # p+

O 1s22s22p4 1s22s22p6

O2- 10 e- 8 p+

F 1s22s22p5 1s22s22p6

F- 10 e- 9 p+

Ne 1s22s22p6 1s22s22p6

Ne 10 e- 10 p+

Na 1s22s22p63s1

1s22s22p6 Na+ 10 e- 11 p+

Mg 1s22s22p63s2

1s22s22p6 Mg2+ 10 e- 12 p+

Prediction: smallest to largest: Mg2+ < Na+ < Ne < F-< O2-

Reminder: Atomic Radius

Ionic Radius

• Cations (+) smaller than original atom– remove e-’s greater pull from

nucleus

• Anions (-) larger than original atom– Increased repulsion swells the shell

Ionic Radius

Ionic Radius1. In this table of ionic radii, how is the charge of the ions of elements in groups

1A-4A related to the group number?