Answer:
protons and neutrons have different charges but they have approximately the same mass
Crust. The crust is closest to the core
The salt in the reaction is potassium sulfate compound. A salt is an ionic compound wherein it is one of the products of an neutralization reaction, together with water, where the reactants are a base and an acid. The salt has generally a neutral charge.
Answer: Option (d) is the correct answer.
Explanation:
Atomic number of carbon is 6 and its electronic distribution is 2, 4. Therefore, in order to become stable and completely fill its octet carbon readily share its valence electrons with another atom.
For example, 
A carbon atom is also able to form a double double with valence electrons of other atom.
Thus, we can conclude that a carbon atom has a strong tendency to share electrons.