•Lesson 3 Part

•The Periodic Table

Chapter 18

•Dmitri Mendeleev (1869, Russian)

–Organized elements by increasing atomic

mass.

–Predicted the existence of undiscovered

elements.

Dmitri Mendeleev

•Henry Mosely (1913, British)

–Organized elements by increasing atomic

number. One proton and electron are added

to each element as you go across the table.

–Fixed problems in Mendeleev’s

arrangement.

Henry Mosely

Metallic Character

1

2

3

4 5

6

7

•Metals•Nonmetals•Metalloids

•Metals- good conductors of heat and electricity, Malleable (most metals can be hammered into thin sheets)

•Nonmetals- gases that are poor conductors of heat and electricity at room temperature, Brittle (breaks easily)

•Metalloids- Conduct heat and electricity better than nonmetals but not as well as metals, Can be shiny or dull , Solids

Metallic Character

Table Sections

1

2

3

4 5

6

7

•Representative Elements•Transition Metals

•Inner Transition Metals

Overall Configuration

Table Sections

1

2

3

4

5

6

7

Lanthanides - part of period 6

Actinides - part of period 7

Columns & Rows

1

2

3

4 5

6

7

•Group (Family)•Period

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

181

2

3

4

5

6

7

•Periodic Law

–Properties of elements repeat periodically

when the elements are arranged by

increasing atomic number.

–Moving from left to right in a row of the

periodic table, metallic properties decrease.

Terms

•Valence Electrons–e- in the outermost energy level

•Atomic Radius

•First Ionization Energy–energy required to remove an e- from a neutral atom

Terms

•Atomic Radius–Increases to the LEFT and DOWN

Periodic Trends

1

2

3

4 5

6

7

•First Ionization Energy•Increases to the RIGHT and UP

Periodic Trends

1

2

3

4 5

6

7

•Group # = # of valence e- (except He)–Families have similar reactivity.

•Period # = # of energy levels

Periodic Trends

1A

2A 3A 4A 5A 6A 7A

8A

•Region where there is 90% probability of finding an electron.•Can’t pinpoint the location of an electron•Density of dots represents degree of probability.

Orbital

•Orbitals have different shapes

Orbital

•Electrons can only exist at certain energy levels.

•Low energy levels are close to the nucleus.

•Each energy level (n) can hold 2n2 electrons.

Energy Levels

•Simplified energy levels using Bohr’s idea of circular orbits.

Lithium Atomic #: 3 Mass: 7

# of p: 3 # of e: 3 # of n: 4

Bohr Model Diagrams

p

pn

nn n

p

e-

e-

e-

Can replace with:

3p4n

Maximum e-

Level 1 2e-

Level 2 8e-

Level 3 18e-

Level 4 32e-

• Choose a number between 1 & 50.

• Find your element by the atomic number you picked.

• Make a Bohr Model diagram for your element on a piece of cardstock (make sure you put your name on it because you will be turning it in for a grade).– Round off the mass listed on the table and

subtract the atomic # to find the # of neutrons.– Abbreviate the # of ‘p’ and ‘n’ in the nucleus.

• I have the card stock, yarn, and electrons, protons and neutrons (cereal)

Bohr Model Activity