ASVAB General Science: Physics and Chemistry Concepts 5

Question 1

What is the term for the minimum energy required to start a chemical reaction?

Accepted Answer

Activation energy

Answer

Activation energy is the minimum energy needed to initiate a chemical reaction by breaking existing bonds.

Question 2

Which phenomenon explains why a straw appears bent when placed in a glass of water?

Accepted Answer

Refraction

Answer

Refraction occurs when light changes speed as it passes from one medium (air) to another (water), bending the apparent position of objects.

Question 3

What is the correct representation of water's chemical formula?

Accepted Answer

H₂O

Answer

Water consists of two hydrogen atoms covalently bonded to one oxygen atom, giving the formula H₂O.

Question 4

According to Charles's Law, what happens to the volume of a gas when temperature increases at constant pressure?

Accepted Answer

Volume increases

Answer

Charles's Law states that volume and temperature are directly proportional at constant pressure, so higher temperature means greater volume.

Question 5

Which of the following is NOT a form of potential energy?

Accepted Answer

Kinetic energy of a moving car

Answer

Kinetic energy is the energy of motion, not stored (potential) energy; the other choices are all forms of stored energy.

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