Density is equal to the mass of the substance per volume it occupies. In ths case, the density of gold from literature is 19,300 kg/m3 or 19.3 g/cm3. Given the volume of <span>4.20cm^3 , the mass is obtained by multiplying density and volume to get 81.06 grams of gold</span>
Electromagnetic radiation.
2KOH(aq) + CoBr₂(aq) → 2KBr(aq) + Co(OH)₂(s)
2K⁺ + 2OH⁻ + Co²⁺ + 2Br⁻ → 2K⁺ + 2Br⁻ + Co(OH)₂
K⁺ and Br⁻ are spectator ions
The white powder is called Magnesium oxide. Or it's chemical symbol MgO
<span>they both had their conclusions based on solid evidence</span>