CSET CSET Physical Sciences: Physics and Chemistry 2 — Questions and Answers
Question 1: What is the law of conservation of energy?
- Energy can be created but not destroyed
- Energy can be destroyed but not created
- Energy cannot be created or destroyed, only transformed (Correct answer)
- Energy increases in every chemical reaction
Correct answer: Energy cannot be created or destroyed, only transformed
The law of conservation of energy states that the total energy of an isolated system remains constant—energy can only change form.
Question 2: On the periodic table, elements in the same group (column) share similar:
- Atomic masses
- Number of neutrons
- Chemical properties (Correct answer)
- Boiling points
Correct answer: Chemical properties
Elements in the same group have the same number of valence electrons, giving them similar chemical properties.
Question 3: What is the pH of a neutral solution at 25°C?
- 0
- 7 (Correct answer)
- 10
- 14
Correct answer: 7
A neutral solution has equal concentrations of H⁺ and OH⁻ ions, corresponding to a pH of 7.
Question 4: Which of the following is an example of potential energy?
- A moving car
- Water flowing down a river
- A book resting on a shelf (Correct answer)
- A spinning top
Correct answer: A book resting on a shelf
A book on a shelf has gravitational potential energy due to its position above the ground.
Question 5: The speed of light in a vacuum is approximately:
- 3 × 10⁶ m/s
- 3 × 10⁸ m/s (Correct answer)
- 3 × 10¹⁰ m/s
- 3 × 10¹² m/s
Correct answer: 3 × 10⁸ m/s
The speed of light in a vacuum is approximately 3 × 10⁸ meters per second (about 300,000 km/s).
Question 6: What happens to the volume of a gas when pressure increases at constant temperature (Boyle's Law)?
- Volume increases
- Volume decreases (Correct answer)
- Volume stays the same
- Volume doubles
Correct answer: Volume decreases
Boyle's Law states that pressure and volume are inversely proportional at constant temperature: P₁V₁ = P₂V₂.
CSET CSET Physical Sciences: Physics and Chemistry 2
What is the law of conservation of energy?