An activity to show the difference between liquids using their density

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.

What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell? a. passive transport b. diffusion c. endocytosis d. exocytosisc. endocytosis

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million