Can someone help the crystals have been dissolved in water. Notice the copper (II)sulphate is the blue solution. Sodium hydroxide is the clear solution.

What should I write for description of each

Where are the following questions

Well you can immediately rule out a and d because if a metal were to lose or gain protons, then it would become a different element all together. the answer here is b because the positive symbol with a number refers to how many electrons the metal can give away to become stable.

4km is the total temerature change between 3 km and 7 km

Molar mass ca = 40.078 g/mol  molar mass cacl2 = 110.984 g/mol  % ca = 40.078 x 100 / 110.984 = 36.1