When making a large purchase, you should avoid everything EXCEPT

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.

Which characteristic of water it form droplets? a. low specific heat b. nonpolar structure c. high surface tension d. ability to dissolve substances

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole