If you have 20 grams of parent material, and one half-life goes by, how much parent material do you have remaining?

How manyatoms of mercury are in 1.4214e+1 ml sample

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]

Atoms contain subatomic particles called protons and neutrons. when these protons and neutrons spilt, a lot of energy is released