Calculate the area of square with is length of 28HM and width of 0.15 HM

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.

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.

Select all that apply. a beta particle: is electromagnetic energy is an electron has zero charge is emitted from the nucleus has a +2 charge has a -1 charge