In electrons are gained by atoms and lost by others. a) ionic bonds b) covalent bonds c) metallic bonds d) polyatomic bonds

The correct answer is Option A.

Explanation:

From the given options:

A. Ionic bonds: These bonds are formed when there is complete transfer of electrons from one atom to another atom. An atom which looses electrons is known as electropositive atom and the atoms which gains electrons is known as electronegative atom.

B. Covalent Bonds: These bonds are formed when there is sharing of electrons between the two atoms.

C. Metallic bonds: These bonds are formed from the attraction between the free electrons and fixed positively charged of two metallic atoms.

D. Polyatomic Bonds: These bonds are formed between the species forming a polyatomic ion.

From the given information, the correct answer to this question is Option A.

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%