Physical Science (Grade 8) Midterm — Semester 1, Form A
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Free printable Physical Science midterm (Grade 8): 15 multiple-choice questions plus 1 written response covering Matter & Its Properties, Atoms & the Periodic Table, Chemical Reactions. Answer key included — customize it in the Midterm Maker.
Physical Science (Grade 8) Midterm — Semester 1, Form A
Name: Date: Period:
Directions: Read each question carefully and choose the best answer. Answer the written response in complete sentences.
Covers: Matter & Its Properties · Atoms & the Periodic Table · Chemical Reactions
Part 1: Multiple Choice
-
Which of these is a mixture?
- A. Pure water
- B. Oxygen gas
- C. Table salt
- D. Salt water
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A rock has a mass of 60 g and a volume of 20 cm³. What is its density?
- A. 0.33 g/cm³
- B. 3 g/cm³
- C. 80 g/cm³
- D. 1200 g/cm³
-
In which state of matter do particles move fastest and spread farthest apart?
- A. Gas
- B. Liquid
- C. Solid
- D. Frozen solid
-
Which of these is a chemical property?
- A. Boiling point
- B. Flammability
- C. Color
- D. Density
-
Dry ice changing directly from a solid to a gas is called what?
- A. Sublimation
- B. Condensation
- C. Melting
- D. Evaporation
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Elements in the same group react in similar ways because they have the same number of what?
- A. Neutrons
- B. Protons
- C. Total electrons
- D. Valence electrons
-
What element does the symbol Na represent?
- A. Nitrogen
- B. Nickel
- C. Sodium
- D. Neon
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An atom has 6 protons and 6 neutrons. What is its mass number?
- A. 12
- B. 6
- C. 36
- D. 18
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Which particle in the nucleus has a positive charge?
- A. Neutron
- B. Photon
- C. Proton
- D. Electron
-
Which group of elements is known for being very unreactive?
- A. Halogens
- B. Alkali metals
- C. Noble gases
- D. Alkaline earth metals
-
How many hydrogen atoms are shown in 2H₂O?
- A. 2
- B. 6
- C. 4
- D. 3
-
Increasing the temperature of reactants usually has what effect on reaction rate?
- A. It slows down the reaction
- B. It has no effect
- C. It stops the reaction
- D. It speeds up the reaction
-
Which coefficients balance the equation ___ H₂ + ___ O₂ → ___ H₂O?
- A. 2, 1, 2
- B. 2, 2, 1
- C. 1, 2, 2
- D. 1, 1, 1
-
A reaction that releases heat to its surroundings is called what?
- A. Endothermic
- B. Exothermic
- C. Physical
- D. Neutral
-
In a sealed container, 12 g of substance A reacts completely with 8 g of substance B. What is the total mass of the products?
- A. 4 g
- B. 12 g
- C. 20 g
- D. 96 g
Part 2: Written Response
- You are given an irregular rock, a balance, and a graduated cylinder of water. Explain step by step how to find the rock's density and how to predict whether it will float.
Answer Key — Physical Science (Grade 8) Midterm — Semester 1, Form A
- D — Salt water Salt water combines two substances that keep their own properties.
- B — 3 g/cm³ Density = mass ÷ volume = 60 ÷ 20 = 3 g/cm³.
- A — Gas Gas particles have the most energy and fill any container.
- B — Flammability Flammability describes how a substance reacts to form new substances.
- A — Sublimation Sublimation skips the liquid state.
- D — Valence electrons Valence electrons determine how an element bonds.
- C — Sodium Na comes from natrium, the Latin name for sodium.
- A — 12 Mass number = protons + neutrons = 6 + 6 = 12.
- C — Proton Protons are positive; neutrons have no charge.
- C — Noble gases Noble gases have full outer electron shells.
- C — 4 Each H₂O has 2 hydrogen atoms; 2 × 2 = 4.
- D — It speeds up the reaction Faster particles collide more often and with more energy.
- A — 2, 1, 2 2H₂ + O₂ → 2H₂O gives 4 H and 2 O on each side.
- B — Exothermic Exo- means 'out'; energy flows out as heat.
- C — 20 g Mass is conserved: 12 g + 8 g = 20 g.
Written Response — Look-Fors
- Measure mass on balance; measure volume by water displacement (final − initial); density = mass ÷ volume with units (g/cm³); compares to water's 1.0 g/cm³ to predict sink/float.