8th grade Science practice sheet
Alabama Course of Study · from Gradelings · Name: ______________________
Question 1
In salt water, which is a solute?
🧪- water
- salt
- salt water
salt
Hint: The solute is what dissolves (usually the smaller amount). The solvent does the dissolving (usually the larger amount). Together they make the solution.
Question 2
Water has a density of 1.00 g/cm³. Does each material float or sink in water?
Sort into: 🛟 Floats · ⚓ Sinks
- 🥫aluminum (2.7 g/cm³)
- 🪵pine wood (0.5 g/cm³)
- 🍾cork (0.24 g/cm³)
- 🫒vegetable oil (0.92 g/cm³)
- 🎣lead (11.3 g/cm³)
- 🧊ice (0.92 g/cm³)
- 🔩iron (7.9 g/cm³)
- 🪙copper (8.9 g/cm³)
🛟 Floats: pine wood (0.5 g/cm³), cork (0.24 g/cm³), vegetable oil (0.92 g/cm³), ice (0.92 g/cm³) · ⚓ Sinks: aluminum (2.7 g/cm³), lead (11.3 g/cm³), iron (7.9 g/cm³), copper (8.9 g/cm³)
Hint: A material floats if its density is less than 1.00 g/cm³ and sinks if it is greater.
Question 3
An atom's center is called the…
- shell
- electron
- nucleus
- molecule
nucleus
Hint: The nucleus holds protons and neutrons.
Question 4
Which of these elements is a metal?
- oxygen
- copper
- carbon
- sulphur
copper
Hint: Metals are usually shiny, bendable and good conductors. Copper is used in electrical wires.
Question 5
Group 18 elements, such as neon and argon, are called the…
- alkali metals
- halogens
- metalloids
- noble gases
noble gases
Hint: Noble gases are very unreactive.
Question 6
Rust forms when iron reacts with…
- oxygen and water
- sugar
- sunlight only
- salt only
oxygen and water
Hint: Oxidation.
Question 7
40 g of one substance reacts completely with 39 g of another in a closed container to form one product. What is the mass of the product?
- 1 g
- 84 g
- 76 g
- 79 g
79 g
Hint: Mass is conserved, so the product has the same total mass as the reactants: 40 + 39 = 79 g.
Question 8
Velocity is speed with…
- a color
- a temperature
- a mass
- a direction
a direction
Hint: Which way?
Question 9
Balanced forces on an object cause…
- a faster speed
- a turn
- no change in its motion
- acceleration
no change in its motion
Hint: A book on a table has balanced forces.
Question 10
By Newton's second law, if you push a cart harder, it will…
🛒- get heavier
- not change at all
- speed up less
- speed up more
speed up more
Hint: More force on the same mass means more acceleration.
Answer key
- 1. salt (Mixtures & Solutions)
- 2. 🛟 Floats: pine wood (0.5 g/cm³), cork (0.24 g/cm³), vegetable oil (0.92 g/cm³), ice (0.92 g/cm³) · ⚓ Sinks: aluminum (2.7 g/cm³), lead (11.3 g/cm³), iron (7.9 g/cm³), copper (8.9 g/cm³) (Density & Buoyancy)
- 3. nucleus (Particles & Matter)
- 4. copper (Atoms & Elements)
- 5. noble gases (The Periodic Table)
- 6. oxygen and water (Chemical Reactions)
- 7. 79 g (Chemical Change)
- 8. a direction (Speed, Velocity & Motion Graphs)
- 9. no change in its motion (Motion, Forces & Newton’s Laws)
- 10. speed up more (Newton's Laws)
Want more than 10 questions?
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