Ecosystems & Food Webs
What do we call organisms like plants that make their own food using sunlight?
Producers
What is the process called when liquid water turns into water vapor and rises into the air?
Evaporation
What causes day and night on Earth?
Earth's rotation (spinning on its axis)
True or False: The sun is a star
True
When you tear a piece of paper in half, is that a physical change or a chemical reaction?
Physical
In a food chain, what do we call animals that only eat plants?
Herbivores
What do we call it when water vapor cools and turns back into liquid water, forming clouds?
Condensation
How long does it take Earth to complete one full rotation on its axis?
24 hours
Which planet is closest to the sun?
Mercury
What are three signs that a chemical reaction might be happening
Color change, temperature change, gas/bubbles forming, light produced, new smell
What important role do decomposers like mushrooms and bacteria play in an ecosystem?
They break down dead organisms and return nutrients to the soil
Name two forms of precipitation
Rain, Snow, Sleet, Hail...
What causes the seasons on Earth?
Earth's tilt on its axis as it orbits the sun
What is the largest planet in our solar system?
Jupiter
Is ice melting into water a physical change or a chemical reaction? Why?
Physical change - it's still water, just in a different state; no new substance is formed
If all the hawks disappeared from a grassland ecosystem, what would likely happen to the mouse population and why?
The mouse population would increase/grow because their predator is gone and nothing is controlling their numbers
How do plants participate in the water cycle through their leaves?
Through transpiration - they release water vapor into the air through their leaves
Why do we see different constellations in the summer than we do in the winter?
Because Earth orbits around the sun, our nighttime view faces different directions in space at different times of year
Why do planets orbit around the sun instead of floating away into space?
The sun's gravity pulls them and keeps them in orbit
When wood burns in a fire, is this a physical change or chemical reaction? How do you know?
Chemical reaction - new substances are formed (ash, smoke, gases) and you cannot turn them back into wood
Explain why a food web is more realistic than a food chain for showing how energy moves through an ecosystem
A food web shows that most organisms eat multiple things and are eaten by multiple predators, while a food chain only shows one path
Explain why the ocean doesn't just evaporate away even though the sun is constantly heating it
The water that evaporates eventually falls back as precipitation, and water is constantly cycling through evaporation, condensation, and precipitation
If you observe the moon at the same time every night for a month, what pattern would you notice and why does this happen?
The moon's shape appears to change through phases because we see different amounts of the sunlit side as the moon orbits Earth
Name three things that make Earth suitable for life that other planets in our solar system don't have.
Liquid water, oxygen in the atmosphere, suitable temperature range, protective atmosphere
Explain the difference between a physical change and a chemical reaction using the idea of "new substances."
In a physical change, no new substance is created (same material, different form). In a chemical reaction, new substances with different properties are created and you usually can't reverse it easily