The answer is A.
During any chemical change the total mass doesn’t changes. Whatever the total mass of starting materials was present the same mass of ending products is present in a chemical reaction.
In an atom, electrons travel outside the nucleus.
c. travel outside the nucleus.
Answer is: oxidation number of nitrogen is +5 (<span>3. 5).
Oxygen has greater electronegativity than nitrogen, so oxygen has negative oxidation number, in this compound -2, so oxidation number of nitrogen is +5:
2 </span>· x + 5 · (-2) = 0.
2x = 10.
x = 10 ÷ 2.
x = 5; oxidation number of nitrogen.
<span>The sum of the oxidation numbers in a neutral compound is zero.</span>