What do we call the path of a planet around the Sun?
Orbit
Which organ system transports blood around the body?
Circulatory system
What are the three states of matter?
Solid, liquid, gas
What force pulls objects toward the Earth?
Gravity
What has keys but can’t open locks?
A piano
Which gas makes up most of Earth’s atmosphere?
Nitrogen
What gas do humans breathe in for respiration?
Oxygen
What is the smallest particle of an element?
Atom
What is the unit of force?
Newton (N)
The more you take, the more you leave behind. What am I?
Footsteps
What causes day and night on Earth?
Earth’s rotation on its axis
Which nutrient is the main source of energy in our diet?
Carbohydrates
What happens to particles during evaporation?
They gain energy and escape from the surface as gas
Which type of energy is stored in a stretched elastic band?
Elastic potential energy
I am light as a feather, yet the strongest person can’t hold me for long. What am I?
Breath
What natural satellite orbits the Earth?
The Moon
What happens to the rib cage and diaphragm when we breathe in?
Rib cage moves up and out, diaphragm moves down
What type of change is rusting: physical or chemical?
Chemical
What is the speed of a car traveling 100 m in 20 s?
5 m/s
Forward I am heavy, but backward I am not. What am I?
Ton
Why do we have seasons?
Because of the tilt of Earth’s axis as it orbits the Sun.
Explain the difference between aerobic and anaerobic respiration.
Aerobic uses oxygen and releases more energy; anaerobic does not use oxygen and releases less energy (produces lactic acid in humans).
Explain why mass is conserved in a chemical reaction.
Atoms are rearranged but not created or destroyed.
State the difference between renewable and non-renewable energy sources.
Renewable sources can be replaced naturally (e.g., solar, wind), non-renewable will eventually run out (e.g., coal, oil).
I speak without a mouth and hear without ears. What am I?
An echo