Are elements always transparent

No, the elements are not always transparent.

Explanation:

The elements become transparent when the light passes through those elements. Transparency is caused because of the transmission and the passing of the light waves through these elements.

But the metals do not become transparent even when the light waves pass through these metals. Metals do not become transparent because the refractive index in them is very big.

answer is d because it is trust me

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%