Which of the following is an atom that has gained an electron? select one: a. positive ion b. nonpolar molecule c. polar molecule d. negative ion

Long-period comets come from the oort cloud particles in earth’s atmosphere material from the asteroid belt the kuiper belt

Hormones are chemical molecules produced by endocrine glands. one such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles. which two statements describe the probable reason for the function of the hormone? the cells in the heart have specific receptors that allow for the intake of hormones. the heart and the endocrine glands have the exact same types of cells. all cells make the same types of hormones. thyroid hormones show their effect on the heart by means of specialized cells. thyroid cells and cardiac cells have different dna.

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic