protons 1.673*10 ^ - 27 kg 1.6*10 ^ -19 C in the nucleus neutrons 1.675*10 ^ - 27 kg 0 in the nucleus electron 9.11 * 10 ^ - 31 kg -1.6 * 10 ^ - 19 C around the nucleus (orbitals)
Protons and neutrons have almost same masses. Mass of electrons is 1/1840 the mass of the protons.
Protons and electrons have the same magnitud of charge with different sign. Protons are positive and electrons are negative. Neutrons do not have charge.
Alkali metal hydroxides can be used to test the identity of metals in certain salts. The colour of the precipitate will help identify the metal : Calcium hydroxide is soluble; no precipitate is formed.