Grade 9 Science practice sheet
Ontario Curriculum · from Gradelings · Name: ______________________
Question 1
Four trials of a reaction took 18, 21, 14, 11 seconds. What is the mean time, in seconds?
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16
Hint: Add the four times and divide by 4: the total is 64, and 64 ÷ 4 = 16.
Question 2
Producer, consumer or decomposer? Sort each organism.
Sort into: 🌱 Producer · 🦌 Consumer · 🍄 Decomposer
- 🦌white-tailed deer
- 🌾cattails
- 🐛earthworms in compost
- 🌿algae in a lake
- 🍄mushrooms on a fallen log
- 🦫beaver
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🌱 Producer: cattails, algae in a lake · 🦌 Consumer: white-tailed deer, beaver · 🍄 Decomposer: earthworms in compost, mushrooms on a fallen log
Hint: Producers make their own food. Consumers eat other organisms. Decomposers break down dead matter.
Question 3
In 6 CO₂, how many oxygen atoms are there altogether?
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12
Hint: Each CO₂ has 2 oxygen atoms, and 6 × 2 = 12.
Question 4
Which is a greenhouse gas?
- helium
- nitrogen
- argon
- methane
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methane
Hint: Carbon dioxide, methane, nitrous oxide and water vapour trap heat. Nitrogen, argon and helium do not.
Question 5
Oxygen (O) has atomic number 8 and mass number 16. How many neutrons are in the nucleus of one atom?
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8
Hint: Neutrons = mass number − atomic number = 16 − 8 = 8.
Question 6
Lithium has electrons arranged 2, 1. Which period (row) is it in?
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2
Hint: The number of occupied shells is the period number: 2.
Question 7
Physical or chemical property? Sort each.
Sort into: 📏 Physical property · 🧪 Chemical property
- 🔌Copper conducts electricity
- 🧂Salt dissolves in water
- ⚗️Baking soda reacts with vinegar
- ♨️Water boils at 100 °C
- 🟤Iron rusts in damp air
- ⚫Silver tarnishes
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📏 Physical property: Copper conducts electricity, Salt dissolves in water, Water boils at 100 °C · 🧪 Chemical property: Baking soda reacts with vinegar, Iron rusts in damp air, Silver tarnishes
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 8
An object has 23 protons and 20 electrons. Which describes it?
- negatively charged
- positively charged
- neutral
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positively charged
Hint: Fewer electrons than protons gives a net positive charge.
Question 9
What is the SI unit of potential difference (voltage)?
- joule (J)
- volt (V)
- ampere (A)
- ohm (Ω)
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volt (V)
Hint: Potential difference is the energy given to each unit of charge. Its symbol is V.
Question 10
A solar cell changes…
- sound to heat
- light energy to electrical energy
- electrical energy to light
- heat to sound
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light energy to electrical energy
Hint: A solar cell is a source, not a load.
Answer key
- 1. 16 (Think Like a Scientist)
- 2. 🌱 Producer: cattails, algae in a lake · 🦌 Consumer: white-tailed deer, beaver · 🍄 Decomposer: earthworms in compost, mushrooms on a fallen log (Ecosystems in Balance)
- 3. 12 (Photosynthesis & Respiration)
- 4. methane (Climate Change)
- 5. 8 (Inside the Atom)
- 6. 2 (The Periodic Table)
- 7. 📏 Physical property: Copper conducts electricity, Salt dissolves in water, Water boils at 100 °C · 🧪 Chemical property: Baking soda reacts with vinegar, Iron rusts in damp air, Silver tarnishes (Elements & Compounds)
- 8. positively charged (Static Electricity)
- 9. volt (V) (Circuits & Ohm's Law)
- 10. light energy to electrical energy (Electrical Energy)
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.