2. What is the difference between a formula unit for an ionic compound and a molecular formula

for a molecule?

Explanation:

In chemistry, a formula unit refers to the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. A formula unit is thus the lowest whole number ratio of ions represented in an ionic compound.

While

A molecular formula comprises the chemical symbols for the constituent elements, followed by numeric subscripts specifying the number of atoms of each element present in a molecule.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.