ASVAB General Science: Physics and Chemistry Concepts 3 — Questions and Answers
Question 1: Which of the following is an example of a chemical change?
- Ice melting
- Water evaporating
- Iron rusting (Correct answer)
- Glass breaking
Correct answer: Iron rusting
Iron rusting is a chemical change because it produces a new substance (iron oxide) through oxidation.
Question 2: What is the unit of electrical resistance?
- Ampere
- Volt
- Watt
- Ohm (Correct answer)
Correct answer: Ohm
Electrical resistance is measured in ohms (Ω), as defined by Ohm's law (V = IR).
Question 3: According to Newton's Third Law, when you push a wall, the wall pushes back with:
- Less force
- More force
- An equal and opposite force (Correct answer)
- No force
Correct answer: An equal and opposite force
Newton's Third Law states every action has an equal and opposite reaction, so the wall exerts an equal force back.
Question 4: What is the atomic number of an element?
- The number of neutrons in the nucleus
- The number of protons in the nucleus (Correct answer)
- The total mass of the atom
- The number of electrons in the outer shell
Correct answer: The number of protons in the nucleus
The atomic number equals the number of protons in the nucleus and uniquely identifies each element.
Question 5: Which state of matter has a definite volume but no definite shape?
- Solid
- Liquid (Correct answer)
- Gas
- Plasma
Correct answer: Liquid
Liquids have a definite volume but take the shape of their container, unlike solids (fixed shape) or gases (no fixed volume).
Question 6: What is the speed of light in a vacuum approximately equal to?
- 3 × 10⁶ m/s
- 3 × 10⁸ m/s (Correct answer)
- 3 × 10¹⁰ m/s
- 3 × 10⁴ m/s
Correct answer: 3 × 10⁸ m/s
The speed of light in a vacuum is approximately 3 × 10⁸ meters per second (about 186,000 miles per second).
Question 7: In a series circuit with two resistors, how does the total resistance compare to each individual resistor?
- It equals the smaller resistor
- It is less than either resistor
- It equals the sum of both resistors (Correct answer)
- It equals the product of both resistors
Correct answer: It equals the sum of both resistors
In a series circuit, total resistance = R₁ + R₂; resistances simply add together.
ASVAB General Science: Physics and Chemistry Concepts 3
Which of the following is an example of a chemical change?