What makes up a virus and how can it be spread from one organism to another

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.