Which of these items is a simple machine?
1. Battery
2.Axe
3.Lighter
4. Toaster

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

How many moles are equal to 2.4×10^23 formula units of sodium chloride