Need !

which of the following is true about the concept of half-life?

a. half-life measures the rate of decay of a radioisotope.

b. the shorter the half-life, the more dangerous the radioisotope.

c. half-life predicts which atoms in a radioactive sample will decay.

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space