Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
The atmosphere is a mixture of gasses.
A covalent bond? Not sure how much detail you want, sorry
A compound<span> is a </span>molecule<span> that contains at least two different elements. </span>All compounds<span> are </span>molecules<span> but not </span>all molecules<span> are </span>compounds<span>. </span>Molecularhydrogen (H2<span>), </span>molecular<span> oxygen (O</span>2<span>) and </span>molecular<span> nitrogen (N</span>2) are notcompounds<span> because each is composed of a single element.</span>
