What is the mass of the Earth?

Which statement correctly describes two forms of oxygen, O2 and O3? (1) They have identical molecular structures and identical properties. (2) They have identical molecular structures and different properties.

Carbon-12 and carbon-13 are isotopes of carbon. Which of the following statements is correct? They both have seven protons in the nucleus. They both have the same mass number. They both have seven neutrons in the nucleus.

Why is atmospheric pressure much lower on the top of a mountain than it is as sea level?

What volume of nitrogen gas is produced by the explosion of 65.0 g of sodium azide at STP? The balanced chemical equation is 2 NaN3 (s) = 2 Na (s) + 3 N2 (g) for this reaction. a. 33.6 L b. 67.2 L c. No right choice.

What is the molality of an aqueous KCl solution with a mole fraction of KCl, XKCl = 0.175? (The molar mass of KCl = 74.55 g/mol and the molar mass of H2O is 18.02 g/mol.)

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?

Convert 970. mm Hg to atm.