Which cup of water gets the hottest, if the initial temperature of all cups is the same?
A. 800 cal added to 100 g of water
B. 350 cal added to 50 g of water
C. 1000 cal added to 150 g of water
D. 500 cal added to 80 g of water

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.

Why is the melting of ice a physical change ?

The bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?