Answer:
<em>Green</em><em> </em><em>vitriol</em><em>-</em><em> </em><em>FeSO4·7H2O</em>
<em>white</em><em> </em><em>vitriol</em><em>-</em><em> </em><em>ZnSO₄</em>
15. D is correct, exothermic reactions release heat
I am not sure about 16
Answer:
The answer is

Explanation:
The energy of a quantum of light can be found by using the formula
<h3>E = hf</h3>
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
f = 4.31 × 10¹⁴ Hz
We have
E = 4.31 × 10¹⁴ × 6.626 × 10-³⁴
We have the final answer as

Hope this helps you