Which of these chemical formulas represents both an element and a molecule?

NaCl

O2

He

SO2

Rank the species (amide ion, ammonia, or ammonium ion) from the largest to the smallest H-N-HH-N-H bond angle? Rank from largest to smallest H-N-HH-N-H bond angle. To rank items as equivalent, overlap them.

How many atoms are there in 5.70 mol of Mg

Why would you not expect to find fossils in metamorphic and igneous rocks?

An antacid tablet dissolving in water is an (A) Endothermic reaction (B) Exothermic reaction

How many sides does a triangle have? I cant figure it out (;

Not all of the water falls as rain, snow, or sleet evaporates. What happens to the rest of the water?

58.5 million excess electrons are inside a closed surface. What is the net electric flux through the surface?.

Nitrogen monoxide and oxygen, both colorless gases, form a red-brown gas when mixed. Nitrogen monoxide and oxygen are called the

What quantity of heat is needed to raise the temperature of 5.0g of a substance from 20 c to 30 c if the specific heat?

Compare mechanical energy and thermal energy.