B What mass of the original isotope will remain after 120 minutes? Ra-226 has a half-life of 1600 years and decays by alpha emission.
A.
What period of time will be required for 20. grams of this radioisotope to decay to 5.0 grams?

Which element is least likely to undergo a chemical reaction

How is energy related to the change of state represented by the model? atoms gain energy as a solid changes to a liquid. atoms gain energy as a solid changes to a gas. atoms lose energy as a solid changes to a liquid. atoms lose energy as a solid changes to a gas.

Why is the bottom layer of a trophic pyrimid the