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

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

Calculate the ratio of h+ ions to oh– ions at a ph = 7. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 7. are they the same? why or why not? record your comparison in table a. what is the concentration of h+ ions at a ph = 7? mol/l what is the concentration of oh– ions at a ph = 7? mol/l what is the ratio of h+ ions to oh– ions at a ph = 7? : 1

All cells are made of four types of acids, lipids, proteins, and carbohydrates.