The answer is gonna be the last one :)
Ionic bonds usually occur between metal and nonmetal ions. For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl. In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals.
Explanation:
When magnesium metal burns is heated i the air it forms magnesium oxide.The balanced chemical reaction is given as:

2 moles of magnesium metal when reacts with 1 moles of oxygen it gives 2 moles of magnesium oxide which is white in color.
Some times along with formation of magnesium oxide small amount of magnesium nitride also produced due to which magnesium oxide appears grey in color .The balanced chemical reaction is given as:

3 moles of magnesium combines with 1 mol of nitrogen gas to to give 1 mol of magnesium nitride.
Answer:
V₂ = 236.84 mL
Explanation:
The relation between pressure and volume is inverse.
We can write it as follows :

We have,
P₁ = 360 torrs, V₁ = 750 mL, P₂ = 1.5 atm = 1140 torr.
So,

So, the new volume of the gas is 236.84 mL.
Correct Answer: Option C i.e <span>Solution
Reason:
Solutions are characterized by particles of size less than 1nm. Since the particle size in solutions are very small, they cannot be separated by centrifugation. On other hand, colloids have particle size ranging from 1nm to 100 nm, while suspensions have particle size > 100 nm. Hence, they can be separated by centrifugation. </span>