Unit 6

Question 1

group 1 alkali metals

Answer 1

• lithium
• sodium
• potassium
• rubidium
• caesium
• francium

Question 2

physical properties of alkali metals

Answer 2

• low melting/boiling points
• very soft so can be cut
• low densities

Question 3

lithium reaction with water

Answer 3

• bubbles, floats, disappears

- forms lithium hydroxide + hydrogen

Question 4

sodium reaction with water

Answer 4

• bubbles quicker, forms ball, disappears

- forms sodium hydroxide + hydrogen

Question 5

potassium reaction with water

Answer 5

• lilac flame, explosion, disappears

- forms potassium hydroxide + hydrogen

Question 6

reactivity in group 1

Answer 6

increases as you go down as the outer shell electron is further away from the pull of the nucleus as they is more shells

Question 7

group 7 halogens

Answer 7

• fluorine
• chlorine
• bromine
• iodine
• astatine

Question 8

electrons of halogens

Answer 8

simple, diatomic molecules and are joined by a single covalent bond

Question 9

melting/boiling points in group 7

Answer 9

increase as you go down as molecules become larger and forces are stronger so more energy is needed to overcome them

Question 10

reactivity in group 7

Answer 10

decreases down the group as they only need to gain 1 electron and its harder to attract when further away from the nucleus

Question 11

halogen react with metals

Answer 11

forms ionic compounds called salts

Question 12

halogens react with hydrogen

Answer 12

to form hydrogen halides

Question 13

hydrogen halides

Answer 13

• gases at room temperature
• dissolve in water to form acidic solutions
• used in disinfectants and bleaches

Question 14

halogen displacement reaction

Answer 14

• halogens gain electrons (reduction)

- halide ions lose electrons (oxidation)

Question 15

group 0 noble gases

Answer 15

• helium
• neon
• argon
• krypton
• xenon
• radon

Question 16

noble gases

Answer 16

• colourless gases at room temperature
• made from single atoms so monatomic
• inert as outer shells are full

Question 17

melting/boiling points in group 0

Answer 17

increase as you go down as the atoms are larger and stronger forces so more energy is needed to overcome them

Question 18

helium

Answer 18

used in balloons and airships as less dense than air and not flammable

Question 19

argon

Answer 19

protects metal welding in light bulbs as not flammable so stop filament burning away

Question 20

krypton and xenon

Answer 20

stop flash filament burning in high temperature flashes