<h2>Answer:</h2>
Compound. Option A is correct
<h2>Explanations:</h2>
When two or more different elements combines, a compound is formed. For instance, if carbon and oxygen combines, carbondioxide is formed according to the equation;

From the reaction, carbon and oxygen are the elements while carbondioxide is the compound. Hence we can conclude that a pure substance formed when two or more different elements combine called compound.
Explanation:
Lactic acid is formed during the breakdown of glucose. This is sometimes called "blood sugar."
Answer:
viscosity
Explanation:
one one left is mercury and the other one is honey right?
It would be Magnesium = 1 atom, Oxygen = 2 atoms, Hydrogen = 2 atoms. It has 5 atoms total. There is 1 magnesium and you multiply each element by the the 2 outside the parenthesis to get 2 oxygen and 2 hydrogen.
I think it is gauche.
I know the angle between two atoms in equatorial positions is 60 degrees. and 60 degrees is seen in gauche conformations.