PERIODIC TABLEChapter 6

DO NOW

Which statement is true? (use Periodic Table)

A. Elements in the same column ↕ has same # of outer shell electrons

B. Elements in the same row ↔ has same # of outer shell electrons

HENRY MOSELEY (1914)

Arrangement:Increasing atomic number

Interesting observations: Discrepancies in Mendeleev’s table disappeared (Te

before I)

TOUR OF THE PERIODIC TABLE

Inner Transition Metals

Hydrogen Most common element in universe

charge: 1+ or 1-

Alkali Metal (Group 1, except H) Highly reactive with water Soft and can be easily cut

Charge:1+

Alkaline-earth metal (Group 2) Less reactive than alkali metals Harder than alkali metals

Charge: 2+

Transition metals (d-block) No identical valence electrons (charge varies) Less reactive than group 1 & 2

Inner Transition metals (f-block)

Nuclei are unstable – radioactive (charge varies)

Halogens (Group 17) Most reactive group of non-metals Likes to react with alkalis to produce salts

charge :1-

Noble gases (Group 18) Low chemical reactivity b/c very stable Outermost energy level is full Does not form ions

Glow brightly when an electric discharge is passed through them

ANION: (-) ionsHalogens: Cl gains 1 e-

1s22s22p63s23p5 1s22s22p63s23p6

(Cl) (Cl-)

Ar

PG-7

As you look down a column, the outermost principle energy level __________________. (but the number of valence e-‘s stays the same)

As more and more levels become filled with electrons, the nucleus becomes ______________ effective at attracting the outer electron(s). This is known as the “shielding effect.”

 (As you look down a column, even though the nucleus

theoretically is stronger since it has more protons, it is NOT effective at holding onto the outer electrons.)

Which energy level has NO shielding? ____________Which atom holds onto the outer electron tighter, K or Rb?Why? ____ has one more filled level than ____ and therefore

is _____ effective at holding onto the outermost (valence) electron.

INCREASES

LESS

1

LESS

Rb K

Is the shielding effect an issue with a row?_____Row, Period , Series

Val. n=2 n=2 n=2 n=2 n=2 n=2 n=2 n=2

energy level  filled ____ ____ ____ ___ ___ ____ ___ ____Levels

The energy level is not changing. What is changing?

Is the nucleus getting stronger?_________. Is it effective?________

In a row, ___________ ___________(and not shielding) determines the trend.

1 1 1 1 1 1 1

YES

YES

NUCLEAR CHARGE

NO

PG-8

ATOMIC RADIUS (PG-9)

Distance from nucleus to outer electronsBond radius = ½ distance between nuclei of adjacent atoms.

75092.swf

IONIC RADII (PG-9)

Metals tend to _________ electrons and become ____________ions. (gain or lose) positive or negative) ** (metal ions are ___________than metal atoms)

(smaller or larger)

Non- metals tend to _______ electrons and become __________ ions. (gain or lose) (positive or negative)

 ** (non-metal ions are ______________than non-metal atoms) (smaller or larger)

lose positive

smaller

gain negative

larger

IONIZATION ENERGY (IE) – PG10

Energy required to remove an electron from an atom or ion (form (+) ion).

e+

neutral atom

A + ionizati

on energy

ion el

A +

ec

tron

IONIZATION ENERGY (IE)

Down a Group: Decreases (easier to remove an electron)

Reason:1. more energy levels (outermost electrons are farther from

nucleus)

2. more shielding (less attraction btw p+ & val. e-)

Across a Period: Increases (harder to remove an electron)

Reason:1. more nuclear charge, p+ ↑2. radius decreases Electron-shielding remains the same

Lower down in a column the atoms are larger / smaller and have more attractiveness / shielding so it is easier to remove an e- from the outer shell.

  It is harder/easier to remove an electron from a small atom with

no shielding.

It gets harder/easier to remove that electron as you move to the right as it approaches a perfect octet.

  Which column would be very difficult to go in and remove and

electron from? Noble gases

So the column with the highest Ionization Energy = Group # 18, Noble gases

Ionization Energy pg-10Circle the correction answer & answer the last 2 questions

ELECTRONEGATIVITY (EN)

Down a Group: Decreases (less attraction towards bonding e-)

Reason:1. more energy levels2. more shielding

Across a Period: Increases (more attraction towards bonding e-)

Reason:1. radius decreases (val. e- closer to nucleus)

2. nuclear charge increases, p+ ↑

Electronegativity of Fluorine is > , = , < the electronegativity of hydrogen

Electronegativity of Chlorine is > , = , < the electronegativity of Chlorine

In water, does Hydrogen or Oxygen pull harder on the shared pair of electrons? ____________

Which column does NOT bond with any element (because it has a perfect

octet)? ____________________ (No electronegativity values are assigned)NOBLE GASES

MOLECULE/MOLE/MASS CONVERSIONS FOR DIATOMIC ELEMENTS

Atomic mass:mass in grams = 1 mole of that elementExample: 12 g C = 1 mol C

Molecular mass:mass of a molecule = 1 mole of that moleculeExample: 32 g O2 = 1 mol O2

Diatomic Elements (BrINClHOF): Br2 I2 N2 Cl2 H2

O2 F2

Elements found in pairs