Which particles affect the mass number? Select one:
a. protons, electrons
b. protons, neutrons
c. electrons, neutrons
d. protons only

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Which statement is actually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

The half-life of a certain element is 100 days. how many half-lives will it be before only one eighth of this elementremains?