When a substance goes directly from solid state to a gaseous state as dry ice does?

What is the total number of atoms in the formula Ca (NO3) 2? (1) 7 (2) 2 (3) 3 (4) 9 The answer is 9 but I don't understand why, Can someone explain?

A nuclear reaction only involves valence electrons. True or False?

Which of the following describes a spontaneous reaction?

n an atom, the first energy level can hold electrons. The second energy level can hold electrons. The third energy level can hold electrons.

Which branch of musicology might study the reasons as to why you like rock music and your friend like country music?

How many valence electrons are in atom of sulfur?

My sister needs this answered! Donald is creating an experiment to determine if fertilizer affects plant color. He makes this statement: "If each plant receives a different amount of fertilizer, then the plant's color intensity will change.

What would happen to life if earth were in a different location within the solar system

Substance that undergoes a change in a chemical reaction is a. a product c. a reactant. b. a chemical. d. an enzyme.

List the number of protons, neutrons, and electrons in Iodine-127. (atomic number is 53)