Which describes a radioactive substance?

a. a substance whose nuclei do not stay together

b. a substance that generates radio-wave frequencies

c. a substance that forms positive or negative ions

d. a substance that forms weak molecular bonds

The drawing represents the movement of particles in a substance. what changes of state can this substance undergo

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

Which element is least likely to undergo a chemical reaction