8th grade Science practice sheet
Texas Essential Knowledge and Skills (TEKS) · from Gradelings · Name: ______________________
Question 1
Physical or chemical property? Sort each.
Sort into: 📏 Physical property · 🧪 Chemical property
- 🧂Salt dissolves in water
- 🟤Iron rusts in damp air
- ⚗️Baking soda reacts with vinegar
- ♨️Water boils at 100 °C
- 🔥Wood burns
- 🥇Gold is malleable
📏 Physical property: Salt dissolves in water, Water boils at 100 °C, Gold is malleable · 🧪 Chemical property: Iron rusts in damp air, Baking soda reacts with vinegar, Wood burns
Hint: A physical property can be seen or measured without making a new substance. A chemical property describes how a substance reacts or changes into a new one.
Question 2
25 g of one substance reacts completely with 3 g of another in a closed container to form one product. What is the mass of the product?
- 25 g
- 33 g
- 22 g
- 28 g
28 g
Hint: Mass is conserved, so the product has the same total mass as the reactants: 25 + 3 = 28 g.
Question 3
Doubling the net force on an object (same mass) makes the acceleration…
- halve
- quadruple
- double
- stay the same
double
Hint: Directly proportional.
Question 4
Which part of the electromagnetic spectrum do we feel as heat?
- infrared
- ultraviolet
- radio waves
- X-rays
infrared
Hint: Warm objects give off infrared radiation.
Question 5
Why does cycling matter help keep an ecosystem sustainable?
- Cycling removes all waste from Earth
- New nutrients fall from space each day
- Producers create extra matter as they grow
- Nutrients are reused, so the supply does not run out
Nutrients are reused, so the supply does not run out
Hint: Atoms of carbon, nitrogen and water are used again and again.
Question 6
Which is the correct order from smallest to largest?
- cell → tissue → organ → organ system
- tissue → cell → organ system → organ
- organ system → organ → tissue → cell
- organ → cell → tissue → organ system
cell → tissue → organ → organ system
Hint: Cells form tissues, tissues form organs, and organs work together in organ systems.
Question 7
Sexual reproduction produces offspring with…
- genes from one parent only
- identical genes always
- no genes
- a mix of genes from two parents
a mix of genes from two parents
Hint: Variation.
Question 8
Bacteria becoming resistant to antibiotics is an example of…
- natural selection
- photosynthesis
- erosion
- metamorphosis
natural selection
Hint: Survivors pass on resistance.
Question 9
Vinegar has a pH of about…
- 13
- 10
- 3
- 7
3
Hint: It is an acid.
Question 10
A very massive star ends its life in a huge explosion called a…
- supernova
- nebula
- solar flare
- white dwarf
supernova
Hint: Super bright.
Answer key
- 1. 📏 Physical property: Salt dissolves in water, Water boils at 100 °C, Gold is malleable · 🧪 Chemical property: Iron rusts in damp air, Baking soda reacts with vinegar, Wood burns (Elements & Compounds)
- 2. 28 g (Chemical Change)
- 3. double (Forces, Motion & Momentum)
- 4. infrared (Light & Radiation)
- 5. Nutrients are reused, so the supply does not run out (Cycles & Succession)
- 6. cell → tissue → organ → organ system (Cells & Life Processes)
- 7. a mix of genes from two parents (Genes & Heredity)
- 8. natural selection (Natural Selection)
- 9. 3 (Water, Acids & Bases)
- 10. supernova (Stars, Galaxies & the Universe)
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.