1- Calcium Hydroxide + Calcium Bicarbonate 2- Calcium Bicarbonate + Sodium Carbonate

3- Calcium Sulphate + Sodium Carbonate

4- Sodium compound + Calcium Sulphate

5- Carbon dioxide + Calcium Carbonate

6- Calcium Bicarbonate + Calcium Carbonate

Remember these followings :-

Acid + Base = salt + water

Acid + metal = salt + hydrogen

Acid + carbonates = salt + water + carbon dioxide

Base + ammonium salt = salt + ammonia + water

Base + acidic oxide = salt + water

I hope that you will be clear via these formulas.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.