The answer would be letter A
<span>quartz (SiO2) is a compound. A compud is the combination of two or more elements. It is a compound because three elements are formed, the silicon and the two atoms of oxygen.</span>
The number of protons in an atom is called its atomic number. This number is very important because it is unique for atoms of a given element. All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms
A chemical change creates a new substance
Answer: v=d−at
Explanation: I don't know if this will help
