After James Chadwick discovered the neutron, atomic theory expanded to include isotopes. Isotopes have many practical uses. For example, scientists use the relative amount of carbon-12 to carbon-14 in ancient bones to determine how old they are.

How many neutrons are in an atom of Carbon-147
A 2
B 6
C 8
D 14

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

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.

How many moles are in 7.2 x 10^23 carbon molecules?