7th grade Science practice sheet
New York State Learning Standards · from Gradelings · Name: ______________________
Question 1
How many atoms in total does the formula NH₃ (ammonia) show?
NH₃ammoniaanswer box
4
Hint: A small number after a symbol tells how many of that atom there are. A symbol with no small number means 1. Add them all up.
Question 2
You add more identical bulbs in series to the same battery. What happens to the bulbs?
- Only the first bulb lights up
- Each bulb gets brighter
- Each bulb gets dimmer
- The brightness stays the same
Each bulb gets dimmer
Hint: More bulbs in one loop means more resistance, so less current flows through each bulb.
Question 3
Biotic or abiotic? Sort each part of an ecosystem.
Sort into: 🌱 biotic (living) · 🪨 abiotic (non-living)
- ☀️sunlight
- 🌳a maple tree
- 🐸a frog
- 🦫a beaver
- 🌬️wind
- 🍄a mushroom
- 🪨a boulder
- 🌡️the temperature
🌱 biotic (living): a maple tree, a frog, a beaver, a mushroom · 🪨 abiotic (non-living): sunlight, wind, a boulder, the temperature
Hint: Biotic parts are living things (plants, animals, fungi, bacteria). Abiotic parts are the non-living things, such as sunlight, water, air, rock and temperature.
Question 4
Why is a food web often more stable than a single food chain?
- Each animal eats only one thing
- It has no producers to run out
- It has no top predators
- Consumers can switch to another food source if one declines
Consumers can switch to another food source if one declines
Hint: More links mean more backup options.
Question 5
Primary or secondary succession? Sort each situation.
Sort into: 🪨 primary succession · 🌱 secondary succession
- 🏖️a new sand dune
- 🧊bare rock exposed by a melting glacier
- 🌪️woodland growing back after a storm
- 🔥a forest regrowing after a wildfire
- 🌋a new island formed by a volcano
- 🪵a logged forest left to regrow
- 🌾an abandoned farm field
- 🪨cooled lava with no soil
🪨 primary succession: a new sand dune, bare rock exposed by a melting glacier, a new island formed by a volcano, cooled lava with no soil · 🌱 secondary succession: woodland growing back after a storm, a forest regrowing after a wildfire, a logged forest left to regrow, an abandoned farm field
Hint: Primary succession starts on bare rock or new land with no soil. Secondary succession starts where soil and seeds are still there, such as after a fire or when a field is left alone.
Question 6
Pine trees have needle-shaped leaves with a waxy coating. How does this help in a cold, dry winter?
- It helps them grow flowers
- It reduces water loss from the leaves
- It makes the leaves fall off
- It lets them catch more rain
It reduces water loss from the leaves
Hint: A small surface and a wax layer slow transpiration.
Question 7
Which of these is NOT part of the particle theory of matter?
- Particles are always moving
- There are spaces between particles
- Particles can be created from nothing when matter is heated
- All matter is made of particles
Particles can be created from nothing when matter is heated
Hint: Heating changes motion, not the number of particles.
Question 8
Water has a density of 1.00 g/cm³. Does each material float or sink in water?
Sort into: 🛟 Floats · ⚓ Sinks
- 🔩iron (7.9 g/cm³)
- 🫒vegetable oil (0.92 g/cm³)
- 🪵pine wood (0.5 g/cm³)
- 🎣lead (11.3 g/cm³)
- 🥫aluminum (2.7 g/cm³)
- 🧊ice (0.92 g/cm³)
- 🍾cork (0.24 g/cm³)
- 🪙copper (8.9 g/cm³)
🛟 Floats: vegetable oil (0.92 g/cm³), pine wood (0.5 g/cm³), ice (0.92 g/cm³), cork (0.24 g/cm³) · ⚓ Sinks: iron (7.9 g/cm³), lead (11.3 g/cm³), aluminum (2.7 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 9
An exothermic reaction…
- releases thermal energy
- makes things colder only
- absorbs thermal energy
- releases no energy
releases thermal energy
Hint: Exo = out.
Question 10
The Adirondacks are made of very old rock that formed deep underground. It is at the surface now because…
- it formed last year
- lava poured out yesterday
- the land rose and erosion removed the rock above
- it fell from space
the land rose and erosion removed the rock above
Hint: Uplift plus erosion.
Answer key
- 1. 4 (Atoms & Elements)
- 2. Each bulb gets dimmer (Circuits & Static)
- 3. 🌱 biotic (living): a maple tree, a frog, a beaver, a mushroom · 🪨 abiotic (non-living): sunlight, wind, a boulder, the temperature (Ecosystems)
- 4. Consumers can switch to another food source if one declines (Food Chains & Energy)
- 5. 🪨 primary succession: a new sand dune, bare rock exposed by a melting glacier, a new island formed by a volcano, cooled lava with no soil · 🌱 secondary succession: woodland growing back after a storm, a forest regrowing after a wildfire, a logged forest left to regrow, an abandoned farm field (Cycles & Succession)
- 6. It reduces water loss from the leaves (How Plants Work)
- 7. Particles can be created from nothing when matter is heated (Particles & Mixtures)
- 8. 🛟 Floats: vegetable oil (0.92 g/cm³), pine wood (0.5 g/cm³), ice (0.92 g/cm³), cork (0.24 g/cm³) · ⚓ Sinks: iron (7.9 g/cm³), lead (11.3 g/cm³), aluminum (2.7 g/cm³), copper (8.9 g/cm³) (Density & Buoyancy)
- 9. releases thermal energy (Chemical Reactions)
- 10. the land rose and erosion removed the rock above (Earth's Changing Surface)
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.