DSST Physical Sciences 4

Question 1

What is the net charge of a neutron?

Accepted Answer

0

Answer

Neutrons are subatomic particles found in the nucleus with no electrical charge.

Question 2

According to the first law of thermodynamics, energy in a closed system is:

Accepted Answer

Conserved — neither created nor destroyed

Answer

The first law of thermodynamics states that the total energy of an isolated system remains constant.

Question 3

What is the pH of a solution with a hydrogen ion concentration of 1 × 10⁻⁹ M?

Accepted Answer

9

Answer

pH = −log[H⁺] = −log(10⁻⁹) = 9, indicating a basic solution.

Question 4

A projectile is launched horizontally from a cliff. Which component of its velocity remains constant (ignoring air resistance)?

Accepted Answer

Horizontal velocity

Answer

Horizontal velocity remains constant because no horizontal force acts on the projectile during flight.

Question 5

Which electromagnetic waves have the shortest wavelengths?

Accepted Answer

Gamma rays

Answer

Gamma rays have the shortest wavelengths (less than 10⁻¹¹ m) and highest frequencies in the electromagnetic spectrum.

DSST - DANTES Subject Standardized Tests Practice Test