We have mass. Anything that generally includes atoms is matter
Answer:

Explanation:
Half reaction:
(1)
balance: 
(2)H and O balance in acidic medium:
(3) charge balance:
Hence balanced half-reaction:
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 pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
<h3>What is pH of solution?</h3>
The pH of a solution is defined as the logarithm of the reciprocal of the hydrogen ion concentration [H+] of the given solution.
Concentration of the basic solution, [OH⁻] = 0.000519
pOH = -log[OH⁻]
pOH = -log[0.000519]
pOH = 3.28
<h3>pH of the solution</h3>
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 3.28
pH = 10.72
Thus, the pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
Learn more about pH here: brainly.com/question/26424076