Judy wanted to figure out the mass of her backpack. She put the pack on a
balance and added 3, 6, and 4 kg weights so that the balance was even. What
is the mass of her backpack?

A) 5kg
B) 9kg
C) 10kg
D) 13kg

What is the chemical formula of the following compound

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.