Periodicity and Atomic Structure

Question 1

OIL RIG

Answer 1

Oxidation is lost (electrons)

Reduction is gained (electrons)

Question 2

Ar=

Answer 2

Ar=(mass of isotope x abundance) + (mass of second isotope x abundance) +…
————————————
100

Question 3

% heavier isotope =

Answer 3

% heavier isotope =
Ar - (mass of lighter isotope)
——————————
Heavy isotope - light isotope

Question 4

Melting point in group 17

Answer 4

Melting point increases down group 17 because as the mass of the halogens increases, the London forces strengthen and become harder to break

Question 5

Hydrogen emission spectrum

Answer 5

n=1 : UV radiation
n=2: visible light
n=3: infrared radiation

Question 6

When does the convergence limit occur?

Answer 6

When lines in an emission spectrum get closer together at higher frequencies/energies

Question 7

Dispersion?

Answer 7

The separation of white light into its component colours

Question 8

List three oxides

Answer 8

Basic: for metals, react with acid, produces alkali solution
Amphoteric: for metalloids, react with acids and bases, produce alkali/acid solution
Acidic: for non-metals, react with bases/alkali, produce acidic solution

Question 9

Group 1 reaction with oxygen

Group 1 reaction with water

Answer 9

4X2 (s) + O2 (g) -> 2X2O (s)

2X (s) + 2H20 (l) -> 2XOH (aq) + H2 (g)

Question 10

Group 1 properties

Answer 10

Alkali metals
Highly reactive
Reactions become more vigorous going down group

Question 11

Group 17 properties

Answer 11

Halogens
Non-metals
Diatomic
Reactivity decreases down the group

Question 12

Atomic radius

Answer 12

Increases down a group because atoms have more shells

Decreases across a period because #protons increases, pulling electrons closer

Question 13

Ionic radius

Answer 13

Increases down a group because ions have increasingly more shells

Decreases across a period because # protons increases, pulling electrons closer

Question 14

Ionisation energy

Answer 14

Decreases down a group because atomic size increases, meaning valence electrons are less attracted to nucleus and thus easier to remove

Increases across a period because atomic size decreases (same reason above)

Question 15

Electron affinity

Answer 15

Decreases down a group (very roughly) because size increases and the stronger the attraction between electrons and nucleus, the more energy released

Increases across a period because size decreases (same reason above)

Question 16

Electronegativity

Answer 16

Decreases down a group because size increases meaning less attraction between electrons and nucleus

Increases across a period because nucleus becomes more positive and atom becomes smaller