What is biodiversity?
The variety of living things in an ecosystem or area.
What are the four forces of flight?
Lift, weight (gravity), thrust, and drag.
What causes day and night on Earth?
Earth's rotation on its axis.
What three things do you need for a complete circuit?
A power source, wires (conductors), and a load (device).
What is a chemical change?
A change that creates a new substance with different properties
Name two ways humans depend on forests.
Oxygen production, wood products, medicine, recreation, habitat for animals (any two).
Which force must be greater than weight for an airplane to take off?
Lift.
How long does it take Earth to orbit the Sun?
One year (365.25 days).
What is the difference between a conductor and an insulator? Give one example of each.
Conductors allow electricity to flow (copper, aluminum); insulators block it (rubber, plastic).
Name two signs that a chemical change has occurred.
Color change, temperature change, gas production (bubbles), precipitate formation, light emission (any two)
What is a coniferous tree and give an example?
A tree with needle-like leaves and cones; examples include spruce, pine, fir.
What is Bernoulli's Principle?
Faster-moving air creates lower pressure; this helps create lift over a wing.
Why do we see different constellations in different seasons?
Earth's position in its orbit around the Sun changes our nighttime view of space.
In a series circuit, what happens if one bulb burns out?
The whole circuit breaks and all bulbs go out.
Is dissolving salt in water a physical or chemical change? Why?
Physical change — the salt can be recovered by evaporating the water; no new substance is formed.
How does clear-cutting affect forest biodiversity?
It removes habitat, disrupts food chains, causes soil erosion, and reduces species diversity.
How do birds reduce drag when flying?
Streamlined body shape, tucking in legs, folding wings closer to the body.
What is the difference between a meteor and a meteorite?
A meteor burns up in the atmosphere (shooting star); a meteorite reaches Earth's surface.
How is a parallel circuit different from a series circuit?
In parallel circuits, electricity has multiple paths; if one device fails, others keep working.
: What happens in a combustion reaction? Give an example.
A substance reacts with oxygen and releases energy (heat/light); examples include burning wood, candles, or gas.
Explain what sustainable forestry means
Managing forests so they can be used by people today while protecting them for future generations.
Compare how a helicopter and an airplane generate lift.
Helicopters use spinning rotor blades; airplanes use fixed wings moving through air.
Explain why the Moon appears to change shape throughout the month.
We see different amounts of the sunlit side of the Moon as it orbits Earth (Moon phases).
What is static electricity and give an example of when you might experience it?
A buildup of electric charge on a surface; examples include shocking a doorknob, rubbing a balloon on hair, lightning.
Explain the difference between an acid and a base, and name one example of each.
Acids taste sour and have pH below 7 (vinegar, lemon juice); bases taste bitter and have pH above 7 (baking soda, soap).