The answer to this question would be: enzyme
<span>Enzyme is a kind of catalyst that </span>will take part in the chemical reaction but it won't be reacted. E<span>nzyme </span>only helps by reducing the energy needed to start the reaction.
Theoretically, the enzyme is not mandatory needed but if you have an enzyme the reaction will be easier, thus increasing reaction speed. But in most case, the reaction might be too slow without enzyme, making enzyme vital in living organism.
scandium is a transition metal and shows a valency of 3.
Molar mass NaCl = 58.44 g/mol
number of moles:
mass NaCl / molar mass
145 / 58.44 => 2.4811 moles of NaCl
Volume = 3.45 L
Therefore :
M = moles / volume in liters:
M = 2.4811 / 3.45
M = 0.719 mol/L⁻¹
hope this helps!
Answer: The answer for this is Compound.
Explanation: A matter is something which occupies space and has some mass.
Elements are defined as the smallest substances which cannot be broken down into another substance by any chemical means.
A compound is a defined as a substance composed of two or more different elements when they combine chemically in definite proportion. For example: 
is named as carbon dioxide and is a compound made by combining carbon and oxygen in a fixed ratio of 1 : 2
So, the answer to the given question is compound.
The number of protons must differ between two different elements
