Element a has 15 protons. determine the number of neutrons in its isotope with mass number 33.

Energy is released during which phase changes? check all that apply. boiling condensing depositing freezing melting subliming

Which of these statements describes the size of an atom? a. an atom is larger than a sheet of aluminum foil. b. an atom is small but can be seen with just our eyes. c. an atom is the size of a plastic building block. d. an atom is tiny and cannot be seen without magnification.

Acompound containing nitrogen and oxygen is decomposed in the laboratory and produces 1.78 g of nitrogen and 4.05 g of oxygen. part a calculate the empirical formula of the compound.