I suppose that the answer is A
Answer:
Compound
Explanation:
-compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
Answer:
If you are asking why the atomic mass on the periodic table only goes to the hundredth's place, it is because of significant figures. No number is exact, like it can be 63.5500001, and it will go to a certain point before it cease to matter in experiments.
Answer: It is element nitrogen. It has an atomic number of 7 and the valence electron is 5. It needs 3 electrons to complete its octet state. That's why sometimes it has the oxidation number of -3 in ammonia.
