An electron and a positron collide and annihilate each other. two photons are produced. explain why two protons must be produced, rather then just one.

The functioning of an electron transport chain is analogous to a) a slinky toy going down a flight of stairs. b) a canoe going over a waterfall. c) a person climbing a flight of stairs one step at a time. d) a person leaping from the top to the bottom of a flight of stairs in one jump.

The act of moving from one place to another. a. locomotor b. aerobic c. stationary d. static

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics