Carbon can combine with many different elements but frequently combines with oxygen, hydrogen, and nitrogen to form organic molecules. Which statement best explains why carbon
is able to form a large number of different molecules?
A.
Carbon forms only ionic bonds.
B. Carbon can form only ring structures.
C. Carbon can form four covalent bonds.
D. Carbon forms small, simple structures.

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Darrel conducted an experiment with the following procedure: fill two cups with ice water. place an uninflated balloon snuggly onto your left index finger. blow a little air into an identical balloon, and place it onto your right index finger. place both fingers into the cups of ice water. darrel noticed that his right finger felt warmer in the ice water than did his left finger. which of the following does the experiment show? a. air is a good radiator of heat. b. air is a good insulator of heat. c. air is a good conductor of heat. d. air is a good convector of heat.

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis