Answer:
Na and Cl
Explanation:
An ionic compound is solid at state room temperature. Therefore Na and Cl would be the correct answer :)
N<span>icolaus </span>Copernicus<span> was a Polish astronomer who put forth the theory that the Sun is at rest near the center of the Universe, and that the Earth, spinning on its axis once daily, revolves annually around the Sun. This is called the heliocentric, or Sun-centered, system.</span>
The answer would be plant cells