Science Quiz

When Zoe mixes baking soda and vinegar in a sealed container, the total mass (a)   .

• It increases

• It decreases

• It stays the same

• It depends on the amounts used

Answer explanation

When Zoe mixes baking soda and vinegar in a sealed container, the total mass stays the same due to the law of conservation of mass. The reactants and products are contained, so no mass is lost or gained.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is an example of a chemical change?

• Boiling water

• Mixing salt and pepper

• Rusting of iron

• Cutting an apple

Answer explanation

Rusting of iron is a chemical change because it involves a reaction with oxygen to form iron oxide, altering the substance's chemical composition. In contrast, boiling water, mixing salt and pepper, and cutting an apple are physical changes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Abigail is making lemonade by dissolving 10 grams of sugar in 90 grams of water. (a)   percentage of the solution is sugar.

• 5%

• 10%

• 15%

• 20%

Answer explanation

To find the percentage of sugar in the solution, divide the mass of sugar (10g) by the total mass of the solution (10g + 90g = 100g) and multiply by 100. (10g / 100g) * 100 = 10%. Thus, the correct answer is 10%.

Match the following scenarios with their outcomes when food coloring is added to water.

• Dropping a stone in water

• It sinks to the bottom

• Heating water to boiling point

• It dissolves and spreads throughout

• Mixing sugar in water

• It floats on top

• Adding oil to water

• It evaporates immediately

Tags

NGSS.MS-PS1-2

When William's ice cream melts, what state of matter does it become?

• Solid

• Liquid

• Gas

• Plasma

Answer explanation

When ice cream melts, it transitions from a solid state to a liquid state. Therefore, when William's ice cream melts, it becomes a liquid.

Tags

NGSS.MS-PS1-4

Evelyn is conducting an experiment to separate salt from saltwater. Which process should she use?

• Filtration

• Evaporation

• Condensation

• Freezing

Answer explanation

Evelyn should use evaporation to separate salt from saltwater. This process involves heating the saltwater to evaporate the water, leaving the salt behind as a solid residue.

Tags

NGSS.MS-PS1-4

Kai has a wooden block and decides to cut it in half. What happens to the mass of the wooden block?

• The total mass increases

• The total mass decreases

• The total mass stays the same

• One half will have more mass than the other

Answer explanation

When Kai cuts the wooden block in half, the total mass remains the same because mass is conserved. Each half will have equal mass, so the total mass does not change.

Charlotte is making a sandcastle and mixes 30 grams of sand with 70 grams of water. After filtering out the sand, the remaining water will weigh (a)  

• 30 grams

• 70 grams

• 100 grams

• It depends on how much water evapor

Answer explanation

After filtering out the sand, only the water remains. Since Charlotte mixed 70 grams of water, the remaining water will weigh 70 grams, making this the correct answer.

Mason is making lemonade and adds sugar to the water. What happens to the sugar molecules when sugar dissolves in the water?

• They are destroyed

• They become water molecules

• They spread out evenly in the water

• They change into a gas

Answer explanation

When sugar dissolves in water, the sugar molecules spread out evenly throughout the water, forming a solution. They do not get destroyed, change into water, or become a gas.

Tags

NGSS.MS-PS1-2

Elijah is conducting an experiment in his chemistry class. He has a mixture and needs to determine which of the following is NOT a characteristic of a solution?

• It is always clear

• It has a uniform composition

• It can be separated by physical means

• It can be a solid, liquid, or gas

Answer explanation

A solution cannot be separated by physical means, as its components are uniformly mixed at the molecular level. The other options describe characteristics of solutions.