(ii) Increases 1 (b) (i) –1 allow Cl – allow – negative 1 (ii) sodium + chlorine sodium chloride → allow correct symbol equation 1 (c) reduce microbes accept sterilise accept prevent diseases allow disinfect allow kill bacteria / germs / microbes / micro-organisms allow to make it safe to drink ignore get rid of bacteria 1 (d) any one from: no freedom of choice • allow unethical fluoride in toothpaste • too much can cause fluorosis • allow too much can cause damage to teeth 1 [6] M5. (a) any two from: react with water or very reactive •
(ii) Increases 1 (b) (i) –1 allow Cl – allow – negative 1 (ii) sodium + chlorine → sodium chloride allow correct symbol equation 1 (c) reduce microbes accept sterilise accept prevent diseases allow disinfect allow kill bacteria / germs / microbes / micro-organisms allow to make it safe to drink ignore get rid of bacteria 1 (d) any one from: • no freedom of choice allow unethical • fluoride in toothpaste • too much can cause fluorosis allow too much can cause damage to teeth 1 [6] M5. (a) any two from: • react with water or very reactive
c2_periodic_table_markscheme.docx