Strontium consists of four isotopes with masses of 84 (abundance 0.50 out of 100), 86 (abundance of 9.9 out of 100), 87 (abundance of 7.0 out of 100), and 88 (abundance of 82.6 out of 100). Calculate the atomic mass of strontium.

Asystem containing an ideal gas at a constant pressure of 1.22×10^5 pa gains 2140 j of heat. during the process, the internal energy of the system increases by 2320 j. what is the change in volume of the gas?

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped