Name a method that could be used to separate magnesium hydroxide from sea water

Add  limewater  

Explanation:

Ca(OH)₂ is about 1000 times more soluble than Mg(OH)₂

If you add limewater to the seawater, the magnesium ions will precipitate out as magnesium hydroxide.

Mg²⁺(aq) + 2OH⁻(aq) ⟶ Mg(OH)₂(s)

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally