PERIODIC TRENDS

• Nuclear Charge• Electron Shielding• Atomic Size• 1st Ionization Energy• Electronegativity• Reactivity

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F = KQ1Q2r2

Coulomb’s Law

Opposites AttractLike Charges Repel

More Charge the greater the force.The more distance the weaker the force

Nuclear Charge

Nuclear Charge Increases

Nuc

lear

Cha

rge

Incr

ease

s

Total electric charge in a nucleus. It is equal to the number of protons.

The Nucleus is what attracts electrons and keeps them in the atom.

Nuclear Charge

The more protons the stronger the nucleus can pull.

PHET PHSYICS

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1s1

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1s22s1

1s1

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1s22s22p63s1

1s22s1

1s1

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1s22s22p63s1

1s22s1

1s1

As you go down a group or column in the periodic table the number of energy levels increases.

Pattern?

1

HHydrogen

1

3

LiLithium

7

11

NaSodium

23

1s22s22p63s1

1s22s1

1s1

As you go down a group or column in the periodic table the number of energy levels increases.

SPDF Blocks

5

BBoron

1

3

LiLithium

7

4

BeBeryllium

23

5

BBoron

1

3

LiLithium

7

4

BeBeryllium

23

5

BBoron

1

3

LiLithium

7

4

BeBeryllium

23

5

BBoron

1

3

LiLithium

7

4

BeBeryllium

23

5

BBoron

11

3

LiLithium

7

4

BeBeryllium

9

As you go across a period the number of energy levels remains constant.

Pattern?

Electron Shielding

--

-- -

-

-

-

-

- -+11Electrons in an atom can shield each other from the pull of the nucleus.

As you go across a period electron

shielding is constant.

As you go down a group electron

shielding increases.

TRENDS

Nuclear Charge Increases

Nuc

lear

Cha

rge

Incr

ease

sEl

ectr

on S

hiel

ding

Incr

ease

s

Electron Shielding Remains Constant