Periodicity

Question 1

1st Ionisation energy

Answer 1

the energy required to remove an electron from a gaseous atom

Question 2

1st Electron affinity

Answer 2

energy change when an electron is added to a gaseous atom

Question 3

Electronegativity

Answer 3

the measure of the ability of an atom to attract a pair of bonded electrons

Question 4

Across a period, the atomic radius _______ because (2 parts)

Answer 4

• electrostatic attraction between protons and electrons increases as the atomic number increases
• electrons are added to the same shell

Question 5

down a group, atomic radii _____ because

Answer 5

increase, extra energy levels are added

Question 6

Electronegativity
______ across a period
_______ down a group

Answer 6

increases, decreases

Question 7

First ionisation energy _____ down a group because

Answer 7

decreases, there is more shielding, the valence electrons are further from the nucleus

Question 8

first ionisation energy _____ across a period because

Answer 8

Increases, protons are added that attract the electrons

Question 9

Na2O reaction with water

Answer 9

Na2O + H2O → 2NaOH (strong base)

Question 10

MgO reaction with water

Answer 10

MgO + H2O → Mg(OH)2 (weak base)

Question 11

P4O10 reaction with water

Answer 11

6H2O + P4O10 → 4H3PO4

Question 12

SO3 reaction with water

Answer 12

SO3 +H2O → H2SO4 (strong acid)

Question 13

Ionic oxides are (basic/acidic)

Answer 13

basic

Question 14

covalent oxides are (basic/acidic)

Answer 14

acidic

Question 15

which group 3 element is amphoteric?

Answer 15

Aluminium

Question 16

Why does the melting point increase down group seven

Answer 16

group seven has van der Waals intermolecular forces, and as you go down the group, there are more electrons, which means more V.d.W forces

Question 17

Why does the melting point decrease down group one?

Answer 17

because the ions are bigger, so the charge is more spread out and the metallic bonds are weaker

Question 18

Down group 1, reactivity _____

Answer 18

increases

Question 19

down group 7, reactivity ____

Answer 19

decreases

Question 20

reaction of Li with water

Answer 20

2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)

Question 21

reaction of Na with water

Answer 21

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

Question 22

reaction of K with water

Answer 22

2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)

Question 23

Which element ends up as an ion in a halide/halogen reaction?

Answer 23

the more reactive element

Question 24

example of halogen reaction with halide ion

Answer 24

Cl2 + I- → Cl- + I2

Question 25

Cl2 (chlorine) colour-

Answer 25

green

Question 26

Br2 (bromine) colour

Answer 26

brownish red

Question 27

I2 (iodine) colour

Answer 27

purple