Leap 2025 Science

Lamar is studying water quality in his science class. He learns that salt water is seeping into his neighboring town’s water supply and makes the water dangerous to drink. Lamar’s teacher challenges his class to investigate ways to identify salt water without tasting it. Part A: Lamar has one glass of pure water and one glass of salt and water. The two liquids look exactly alike. What investigation can Lamar perform, without tasting the water, to find out which glass contains the salt water?

• Lamar couldn’t do it. A chemical change has taken place.

• Lamar could evaporate the water to see which cup leaves salt behind.

• Lamar couldn’t do it. It is not possible to identify clear liquids without tasting them.

• Lamar could shine a light into the water and check for salt conductivity.

Tags

NGSS.MS-PS1-2

Dr. Hoey develops an experiment to investigate how different substances react when they are mixed with water. Before mixing the materials together, she measured the mass and temperature of the substances. During the experiment, Dr. Hoey mixes calcium and water in a glass with a plastic rod. Then, she mixes baking soda and water in a glass with a plastic rod. The results of the experiment are below. Which of the following claims can Dr. Hoey make based on her investigation?

• Solution A is a new substance because after the calcium and water mixed, the temperature increased and the color changed.

• Solution B is a new substance because after the baking soda and water mixed, the solution was cloudy and the temperature remained the same.

• Solution B is a new substance because after the baking soda and water mixed, the mass of the solution is equal to the mass of the baking soda and water before they were mixed.

• Solution A and B are new substances because each solution stayed the same when they were mixed together.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Gravity Keith’s class has been learning about the effects of Earth’s gravity. His teacher challenges his class to imagine that tunnels are dug into the earth. The teacher draws the diagram below and asks the students to think about what would happen if a red ball were released at the entrance of a tunnel. If a small ball, represented by the red dot in the image to the left, is held just above the tunnels, which path (path A, path B, path C, or path D) would it follow when released? Select the best claim Keith could make about the path the ball would take.

• The ball would follow path A because gravity would pull it to the center of the earth.

• The ball would follow path B because gravity would pull the ball down the tunnel at a slant.

• The ball would follow path C because it would be trapped in the earth’s orbit.

• The ball would follow path D because gravity is a force that pull objects down.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

Gas Particles Angela studies three different types of matter in her science class. She claims that air is a gas made of particles too small to be seen. Which two examples provide evidence to support Angela’s claim that gases are made of particles too small to be seen? Select the two correct answers.

• Bubbles in boiling water

• Ice cream melting in a bowl

• Snow forming in clouds

• Melted lava hardening into rock

• A kite floating in the sky

Tags

NGSS.MS-PS1-1

What happens if we didn't have leap years?

• The calendar year would be shorter than the solar year

• The calendar year would be longer than the solar year

• There would be no effect on the calendar or seasons

• The seasons would shift over time

Tags

NGSS.MS-ESS1-1

What is a leap year?

• A year with 366 days

• A year with 364 days

• A year with 365 days

• A year with 367 days

Why is February chosen as the month to have the extra leap day?

• It was the last month of the year in Roman times

• It is the shortest month

• It has the least number of holidays

• It was considered the luckiest month

Question 4: Burning Wood

A chemistry class burned wood in a fume hood in their science laboratory to better understand how the materials would change when burned. Before conducting the experiment, the students measured the mass of the wood in the fume hood. After the experiment, the students measured the mass of the burned wood, the ashes, and the gases in the fume hood.

Which graph best represents the mass of all of the materials before and after burning?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Mixing Substances In science class, Marvin studies the effects of mixing substances together. Marvin and his partner measure and collect 450 mL of warm water and 50 mL of salt in a large, glass beaker. They measure the mass of each substance and record the results in the table below. Part A: Marvin and his partner measured the mass of a large, glass beaker. They mix the two substances together in the beaker. They observed a slight color change in the water and that much of the salt disappeared after mixing the two substances. Then, they measured the mixture and subtracted the mass of the beaker so they could record the mass of the substances after they mixed them together. Which estimate is the mass of the mixture?

• 450 grams

• 909.2 grams

• 454.6 grams

• 445.4 grams

Tags

NGSS.MS-PS1-5

In science class, Marvin studies the effects of mixing substances together. Marvin and his partner measure and collect 450 mL of warm water and 50 mL of salt in a large, glass beaker. They measure the mass of each substance and record the results in the table below.
Part B: Which statement best explains Part A?

• The water was warm and made some of the salt dissolve. When salt dissolves, it loses its mass.

• Marvin and his partner mixed the water and the salt. This made the mass of both substances double.

• The water was warm and made some of the salt dissolve. Both substances lost a little mass because they were mixed together.

• Marvin and his partner combined the water and the salt. The total mass of each substance did not change even though they were mixed together.

Tags

NGSS.MS-PS1-5