<span>Astronomy is a natural science that studies celestial objects and phenomena. More generally, all astronomical phenomena that originate outside Earth's atmosphere are within the purview of astronomy.
Therefore, the correct answer to the question "Astronomy can best be described as a/an" is "study of objects beyond the Earth's atmosphere."</span>
Answer:
alkaline earth metals
Group 2 metals, the alkaline earth metals, have 2 valence electrons, and thus form M2+ ions. The halogens, Group 17 , reach a full valence shell upon reduction, and thus form X− ions
Explanation:
Answer:

Explanation:
Assuming the pith balls as point charges, we can calculate the repulsive force between them, using Coulomb's law:

We observe that the magnitude of the electric force is directly proportional to the product of the magnitude of both signed charges(
) and inversely proportional to the square of the distance(d) that separates them.
Replacing the given values, where k is the Coulomb constant:
