Ecosystems & Energy
What is a producer?
An organism that makes its own food (plants).
Name the three common states of matter.
Solid, liquid, gas
What causes day and night?
Earth’s rotation
A push or pull is called what?
Force
Why do we have seasons on Earth?
Because of the tilt of Earth’s axis as it revolves around the Sun.
What do we call animals that eat only plants?
Herbivores
Is melting butter a physical or chemical change?
Physical
How long does it take Earth to orbit the Sun?
1 year
What happens when forces are balanced?
no change in motion
If all the grass in a meadow dies, how might it affect the herbivores and carnivores?
Herbivores would have less food, so their population might decrease, which then affects carnivores.
Where does almost all energy in a food chain begin?
The Sun
What happens to particles when matter is heated?
They move faster.
What causes the phases of the Moon?
Moon’s position relative to Earth and Sun
What force pulls objects toward Earth?
gravity
A book slides across a table and stops. Why didn’t it keep moving forever?
Friction between the book and table slowed it down and sto
What role do decomposers play?
Break down dead organisms and recycle nutrients.
What is a mixture?
Two or more substances combined but not chemically changed.
What is gravity?
Force that pulls objects toward Earth
Explain how friction affects motion.
Slows objects down by resisting movement.
A shadow is longest in the morning and evening. Why?
Because the Sun is low in the sky, making the angle of sunlight longer.
If a top predator disappears, what might happen to the food web?
Prey population increases, ecosystem imbalance.
Give one example of a chemical change and explain why.
Rusting, burning, baking — new substance forms.
Why do we see different constellations at different times of year?
Earth’s revolution around the Sun
What happens to an object’s motion if an unbalanced force acts on it?
It changes speed and/or direction.
Is melting ice cream a chemical or physical change? How do you know?
Physical change; the substance is still ice cream, no new substance is formed.