a) a substance that increases the rate of a reaction
b) a substance that increases the rate of a reaction but is itself not consumed
c) a substance that produces the desired product faster in a chemical reaction
d) a substance that changes a rate of a reaction.
18. Excited state of an atom is when?,
a) one or more electrons are not in the lowest possible enrgy level
b) when an electron leaves the atom
c) when an atom acquires more energy
d) when an atom has more electrons than it needs
19. Define an atomic mass unit (AMU) according to the IUPAC.
a) 1 amu = 1/12 the mass of Carbon 12
b) 1 amu = 1/16 the mass of Oxygen 16
c) 1 amu = 1/1 the mass of hydrogen
d) 1 amu = the maximum number of protons in an atom.