No, the elements are not always transparent.
<u>Explanation:</u>
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:
Because the most common form of Nickel is Ni-58 while the most common form of Cobalt is Co-59, this means that Cobalt (which is number 27 on the periodic table) has 27 protons and 32 neutrons. Therefore 1 less proton but 2 more neutrons and hence has a greater mass than Nickel.
Explanation: