Rank these elements according to first ionization energy. sb, as, p, n

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Rays from the sun are not considered matter true or false

Use the periodic table to determine how many grams of oxygen would be required to react completely with 859.0 g c2h2