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Teacher Certification · 5485

Praxis Physical Science Practice Test

Praxis Physical Science (5485) practice covers core ideas in chemistry and physics through questions about matter, motion, forces, energy, and waves. The available bank includes atomic structure, chemical reactions, gas behavior, speed, acceleration, force, buoyancy, and wavelength calculations. These topics call for careful use of scientific principles, units, and quantitative relationships.

Exam overview

Exam providerETS Praxis
Exam code5485
CategoryTeacher Certification

About the Praxis Physical Science Exam

Physical science reasoning involves connecting models and measurements to explain observable behavior. In chemistry, distinguish atomic number from mass number, relate protons and neutrons to atomic structure, and recognize that ordinary reactions rearrange atoms rather than change their identities. Gas questions require attention to temperature, pressure, amount of substance, and the ideal gas relationship. In physics, calculate speed and net force, interpret acceleration, and compare buoyant force with an object's weight when analyzing floating equilibrium. Wave problems link speed, frequency, and wavelength, so unit consistency matters. For teaching-related work, these concepts support clear explanations, interpretation of numerical evidence, and identification of misconceptions—for example, confusing mass with weight or assuming atoms are created in a chemical reaction.

Sample Practice Questions

Review a selection from this exam's published US Practice Tests practice bank.

Question 1

An element has atomic number 17. How many protons are in the nucleus of each atom of this element?

  1. A8
  2. B17
  3. C18
  4. D34
Show answerCorrect answer: B

An element’s atomic number is defined as the number of protons in the nucleus. An atom with atomic number 17 therefore has 17 protons.

Question 2

A wave travels at 24 m/s and has a frequency of 6 Hz. What is its wavelength?

  1. A0.25 m
  2. B4 m
  3. C18 m
  4. D144 m
Show answerCorrect answer: B

Wave speed is the product of frequency and wavelength: v = fλ. Thus λ = v/f = 24/6 = 4 m.

Question 3

A block floats at rest in water. Which statement correctly compares the buoyant force on the block with its weight?

  1. AThe buoyant force is greater than the block’s weight.
  2. BThe buoyant force is equal to the block’s weight.
  3. CThe buoyant force is zero.
  4. DThe buoyant force depends only on the block’s color.
Show answerCorrect answer: B

A floating object at rest is in vertical equilibrium. The upward buoyant force balances the downward gravitational force, so the forces are equal in magnitude.

Question 4

A 2.0 kg object accelerates at 3.0 m/s². What is the net force acting on it?

  1. A1.5 N
  2. B5.0 N
  3. C6.0 N
  4. D9.0 N
Show answerCorrect answer: C

Newton’s second law gives F = ma. Multiplying 2.0 kg by 3.0 m/s² gives a net force of 6.0 N.

Question 5

Which statement best describes what happens to atoms during an ordinary chemical reaction?

  1. AThe atoms are rearranged into new combinations.
  2. BThe atoms are converted entirely into energy.
  3. CThe nuclei of all atoms split into smaller nuclei.
  4. DThe atoms disappear as products form.
Show answerCorrect answer: A

In ordinary chemical reactions, bonds break and form, rearranging atoms into different substances. The atoms themselves are generally conserved; nuclear changes are not ordinary chemical reactions.

Question 6

An atom of carbon-14 has 6 protons and 8 neutrons. What is its mass number?

  1. A6
  2. B8
  3. C14
  4. D48
Show answerCorrect answer: C

Mass number is the total number of protons and neutrons in the nucleus: 6 + 8 = 14.

Question 7

A car travels 150 m in 10 s at a constant speed. What is its speed?

  1. A15 m/s
  2. B0.067 m/s
  3. C140 m/s
  4. D1,500 m/s
Show answerCorrect answer: A

Speed is distance divided by time: 150 m ÷ 10 s = 15 m/s.

How to use this practice test

The free practice bank contains 50 published questions; each session presents up to 20 random questions. Work through the calculations and concept questions, then use the results shown after the session to identify which relationships or explanations need another pass. Check units and write out the relevant equation before selecting an answer.

Preparation tips

  • For atomic-structure questions, separate proton count, neutron count, atomic number, and mass number; verify each with a simple example such as carbon-14.
  • Practice rearranging v = fλ and substituting consistent units to find wave speed, frequency, or wavelength.
  • For motion and force problems, distinguish speed from acceleration and apply Fnet = ma with units of newtons.
  • Compare buoyant force and weight for floating objects, and explain why equal opposing forces produce zero vertical acceleration.
  • Use PV = nRT for ideal-gas calculations, converting kilopascals to pascals when using R in joules per mole-kelvin.
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