Select all that apply: Which of the following affect (s) the half-life of a radioactive substance?

A. the type of isotope

B. the temperature of the substance

C. the addition of a catalyst

D. the mass of the substance

What is groundwater?

How does this difference show that whales and animals with four legs are probably descended from a common ancestor?

What can thermal energy can be transferred I conduction from one piece of matter to another only if the two pieces are

How do your muscles continue to get energy during high levels of activity when there is not enough energy?

The students in Mr. Ferrell's class put plants in pots. Then, they put the pots outside in four places. They watched the plants for a week. The weather was mostly sunny, but it rained during three afternoons.

How does skin prevent entry of micro organism in the body

Hank likes to explore nearby streams during the summer. However, one winter there is a lot of rain near the stream. How might the stream change before the next summer? A. The stream will have dried up. B. The stream water will be shallower. C.

A woman with rheumatoid arthritis has taken leflunomide for 1 year. she telephones a nurse and says that the result of a home pregnancy test was positive. the nurse should:

Which of Mendel's laws or principles states that gametes carry one allele for each trait?

What is not a name for a chain of amino acids