Brain Meta

A scientist finds a new object in space. It moves and uses energy from light. Which of

the following must also be true for it to be considered alive?

• It glows in the dark

• It can reproduce and grow

• It reacts only to water

• It is made of metal

A pencil is measured by two students. One says it's 15 cm; the other says it's 150 mm.

Are they correct, and why?

• No, they used different tools

• Yes, 150 mm = 15 cm

• No, one is wrong

• Yes, but they measured different pencils

A balloon is filled with gas. It takes the shape of its container and can be compressed easily. What does this tell us about the particles in a gas?

• They are tightly packed and vibrate

• They are close and slide past each other

• They are far apart and move freely

• They are fixed in place and do not move

Adam mixes iron filings and sand in a beaker. How can he prove that it is a mixture and not a compound?

• Heat it to see if it melts

• Use a magnet to separate the iron

• Add acid to break it down

• Mix it with sugar to form a solution

What would happen if all insects disappeared suddenly from an area with many flowering plants?

• The plants would grow faster

• Pollination would decrease, and fewer fruits would grow

• The soil would become richer

• The plants would start moving to find pollinators

Why is it important to have decomposers like fungi in an ecosystem?

a) They protect plants from animals

b) They help clean water

c) They break down dead matter and return nutrients to the soil

d) They help plants produce more flowers

• They protect plants from animals

• They help clean water

• They break down dead matter and return nutrients to the soil

• They help plants produce more flowers

A heavy box on a smooth floor is harder to stop than the same box on a carpet. What force is acting more on the carpeted floor?

• Gravity

• Friction

• Air resistance

• Magnetism

Which rock type is formed when melted rock cools and hardens?

• Sedimentary

• Metamorphic

• Igneous

• Fossilized

Which material would be the best insulator in an electric circuit?

• Copper

• Silver

• Plastic

• Iron

A pencil is placed in a glass of water and looks bent. What causes this effect?

• Absorption

• Reflection

• Refraction

• Rotation