Which layer contains almost 90% of the atmosphere's total mass?

Which choice is an abiotic factor of an ecosystem A. dogs B. fungi C. ants D. minerals

Copper is added to a solution of nitric acid. The solution becomes hot and changes from colorless to dark blue. What is the best explanation for the change in temperature? A. The copper and nitric acid repel each other, which produces heat. B.

For a family dinner, Jose's mom baked a loaf of bread. During the meal, his grandmother commented, "This bread is so dense!

Are h2o and h2o2 the same compound

What is the percent by mass of water in the hydrate? %

Which explanation best describes a wave? A. a disturbance that travels through a medium with a transfer of energy and matter B. a disturbance that travels through a medium without a transfer of energy and matter C.

The requirements for one type of atom to substitute for another in a solid solution are:

How could you separate items that are different densities? explain

Why do elements within a period of the periodic table have different properties

A professional technician maintains and operates specialized scientific equipment. True False