Which of the following can be said about the sum of the masses of the subatomic particles in an atom's nucleus?
a-the sum is always the same as the mass of the atom
b-the sum is always less than the mass of the atom
c-the sum is always more than the mass of the atom
d-the sum is always zero

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

Chemical energy is a form of a. kinetic energy only. b. both potential and kinetic energy. c. neither potential nor kinetic energy. d. potential energy only. reset

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?