What is the difference between an element and a compound?

Lactic acid and energy are produced in muscle cells during choose 1 aerobic respiration cellular respiration anaerobic respiration cellular division

For this question look at the hydropic diagram water that is heated by the sun evaporates. select the number that represents it.

Which statement describes compounds a. compounds are made of one type of atom. b. compounds cannot be represented by models. c. compounds are represented by chemical formulas. d. compounds cannot be broken down into simpler forms.