Why is air a mixture? i do not understand why air is a mixture. can you guys write a brief explanation about why air is a mixture, whether it is homogeneous or heterogeneous, and how it can be separated.

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.

How many moles are in 43.9 l of oxygen

Technician a says that you should never jump-start a frozen battery. technician b says that a frozen battery can explode, causing injury, when jump-started. who is correct?