when liquid water changes into solid ice, it increases in mass
1 electron has charge =1.602* 10⁻¹⁹ C
1 mole of electrons have 1.602* 10⁻¹⁹*6.02*10²³C = 9.64*10⁴ C/1mol
One ion Co²⁺ takes 2e⁻ to become Co⁰.
1 mol of Co²⁺ ions take 2 mole of e⁻ to become Co⁰, so
0.30 mol Co²⁺ ions take mole of 0.60 mol e⁻ to become Co⁰
9.64*10⁴(C/1mol) *0.60 (mol)≈ 5.8 *10⁴ Coulombs.
Correct answer is C
There are six electrons in the covalent bonds.
Two N atoms would be :N:· + ·:N:
An N₂ molecule would be :N:::N: or :N≡N:
This gives each N atom an octet of eight electrons in its valence shell.
and D. to identify minerals
