Which statement BEST describes electromagnetic and mechanical waves? A.
Electromagnetic waves and mechanical waves both do not require a medium.
B.
Mechanical waves require a medium and electromagnetic waves do not.
C.
Electromagnetic waves require a medium and mechanical waves do not.
D.
Mechanical waves and electromagnetic waves both require a medium.

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

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.

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation: