Which of the following involve endothermic reactions? (select all that apply)

A. A chemical cold pack

B. Gasoline in a car engine

C. Cooking rice

D. A candle flame

How many neutrons are in the element phosphorus?

What must occur in a substance in order to determine a chemical property?

What did Henry Moseley determine that contributed to understanding the atom? A. That each element has a different number of isotopes. B. That each element has a different number of protons. C. That each element has a different number of neutrons. D.

Ammonia gas is dissolved in a 1.00 * 10-4M solution of CuSO4to give an equilibrium concentration of [NH3] = 1.60 * 10-3M. Calculate the equilibrium concentration of Cu2 + (aq) ions in the solution

What is the mass of 3.62X10^24 molecules of methanol

1. Which of the following species determines the chemical properties of an atom? A. Electron B. Neutron C. Nucleus D. Proton 2. The following glasswares are used to measure the volume of liquids except A. graduated beaker B. pipette C. test tube D.

A sample of a certain material has a mass of 2.03 x 10-3 g. calculate the volume of the sample, given the density is 9.133 x 10-1 g/cm3.

What happens to a reactant molecules when forming product molecules

Which is the atomic number of an atom with six valence electrons

O2 + CS2 → CO2 + SO2 Which of the following shows the equation balanced?