8th grade Science practice sheet
Minnesota K-12 Academic Standards · from Gradelings · Name: ______________________
Question 1
In which state are the particles packed closely and only vibrate in place?
- liquid
- gas
- plasma
- solid
solid
Hint: In solids, particles are held in fixed positions and vibrate.
Question 2
Which travels fastest?
- a car
- sound
- a jet plane
- light
light
Hint: Light travels about 300,000 km every second, far faster than sound.
Question 3
Water is H₂O. What does the small 2 tell you?
💧- There are 2 hydrogen atoms for every oxygen atom
- There are 2 oxygen atoms
- Hydrogen weighs 2 times as much as oxygen
- There are 2 water molecules
There are 2 hydrogen atoms for every oxygen atom
Hint: A small number written after a symbol counts the atoms of the element just before it.
Question 4
Each cell gives 1.5 V. If 4 cells are connected in series (end to end), what is the total voltage?
🔋🔋🔋🔋answer boxV
6 V
Hint: Cells in series add their voltages: 1.5 V × 4.
Question 5
An electromagnet is made by…
- rubbing a balloon
- freezing a magnet
- heating a rock
- running current through a coil of wire
running current through a coil of wire
Hint: Electricity makes magnetism.
Question 6
A puck slides much farther on ice than on carpet. Why?
🏒- The ice pushes the puck forward
- The puck has more inertia on ice
- Ice has less friction, so less force slows the puck
- Gravity is weaker over ice
Ice has less friction, so less force slows the puck
Hint: Without a force to slow it, a moving object would keep going. Less friction means less slowing.
Question 7
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 8
Pushing a cart transfers energy to it, so the cart…
- slows down
- speeds up
- gets lighter
- stops
speeds up
Hint: Energy in, motion changes.
Question 9
Baking soda and vinegar fizz. The bubbles are…
- air from the room
- carbon dioxide gas
- water vapor only
- oxygen from the sun
carbon dioxide gas
Hint: A new gas is made.
Question 10
Heat moving by flowing liquids or gases is…
- conduction
- radiation
- convection
- reflection
convection
Hint: Warm air rises.
Answer key
- 1. solid (Particles & Matter)
- 2. light (Light & Radiation)
- 3. There are 2 hydrogen atoms for every oxygen atom (Atoms & Elements)
- 4. 6 V (Circuits & Static)
- 5. running current through a coil of wire (Fields & Forces at a Distance)
- 6. Ice has less friction, so less force slows the puck (Newton's Laws)
- 7. no change in its motion (Motion, Forces & Newton’s Laws)
- 8. speeds up (Kinetic & Potential Energy)
- 9. carbon dioxide gas (Chemical Reactions)
- 10. convection (Thermal Energy & Insulation)
Want more than 10 questions?
In Gradelings the questions change every time and adjust to your child, with hints and kind feedback. See all science units.