Why are some isotopes used as tracers?

a. they leave visible trails.
b. they bind with all molecules.
c. they decay at a predictable rate.
d. they are uniquely identifiable like fingerprints.

Which element is the least metallic between cadmium, silver, zinc, or iron?

Will mark brainliest how many electrons can be held in the energy level n = 4?

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.