An element's atomic number is the
a. weight of the atom.
b. mass of the atom.
c. number of protons in an atom's nucleus.
d. sum of the protons and neutrons in an atom

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine

If there's a small amount of friction between two surfaces, the result could be select all that applya. no movement b. heatc. a little bit of movementd. sliding around