Write the electronic configuration of the Na +, Mg2 +, Ca2 + and Rb + ions. Research the size of these ions in picometers and order them in descending order of their size.

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons? a) 6 b) 8 c) + 1 d) 12 e) 18

What substance has a mass of 9.5g and volume of 2.1cm^3