Which of the following is a noncontact force? a. magnetic forces b. electrical forces c. gravitational forces d. all of these

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

All cells are made of four types of acids, lipids, proteins, and carbohydrates.

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.