The smallest unit of an element that has all the p

ATI RN

ATI RN Test Bank

The smallest unit of an element that has all the properties of that element is a(an):

A. atom B. gas C. molecule D. isotope

Correct Answer: A

Rationale: An atom is the smallest unit retaining an element's chemical properties.

A solution with a pH of 3 would be:

A. acidic B. basic C. neutral D.

Correct Answer: A

Rationale: pH < 7 indicates an acidic solution (high H+ concentration).

Identify the macromolecule that has a 2:1 ratio of hydrogen to oxygen atoms.

A. Carbohydrates B. Lipids C. Nucleic acids D. Proteins

Correct Answer: A

Rationale: Carbohydrates (e.g., C6H12O6) have a 2:1 H:O ratio.

Which of the following is NOT a type of lipid?

A. glycogen B. steroids C. triglycerides D. phospholipids

Correct Answer: A

Rationale: Glycogen is a carbohydrate; steroids, triglycerides, and phospholipids are lipids.

Enzymes allow reactions to occur at normal body temperatures by:

A. decreasing pH B. increasing pH C. decreasing energy of activation D. increasing energy of activation

Correct Answer: C

Rationale: Enzymes lower the activation energy, speeding reactions at physiological temperatures.

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