Dancing molecules

 "It's all about chemistry."

"No, it's all about physics. It makes chemistry happen."

"But I love chemistry and hate physics!"

"Chemistry is protons, neutrons and electrons dancing around each other on a crowded floor. To understand chemistry, you must learn about physics."

"But...."

"There is no 'but'."

"*sigh*"

"Start with water. It's a chameleon. It's the only natural chemical substance that exists in three states: a liquid, solid, and gas. Water changes from one phase to another at specific temperatures and pressures. This is all physics and the basis of interactions with other molecules, what you call chemistry."

"Umm...."

"You can't think of chemistry without physics. 'It is the Way.'"

(based on an actual conversation between me and my late father when I was an undergrad)