Properties of mixtures- progress learning

Josh is designing a lab to separate a mixture of sulfur powder and iron filings. What method should Josh use?

• Density

• Filtration

• Evaporation

• Magnetic attraction

Answer explanation

Josh should use magnetic attraction to separate the mixture because iron filings are magnetic, while sulfur powder is not. This method effectively pulls the iron filings away from the sulfur.

In the image above, ice cubes are turning into liquid water. Which piece of evidence tells you that this is a physical change?

• The size of the ice cube is changing.

• The color of the ice cube is changing.

• The ice cube is getting bigger.

• The shape of the ice cube is not changing.

Answer explanation

The size of the ice cube is changing, indicating a physical change as it melts into water. Physical changes involve alterations in size, shape, or state without changing the substance's chemical identity.

Tags

NGSS.MS-PS1-4

One way to separate certain mixtures, like sand and pebbles, is by using the method shown in this image. Which term best describes this method?

• Evaporation

• Filtration

• Floatation

• Magnetism

Answer explanation

The method shown is best described as filtration, which separates solid particles from liquids or gases. In this case, sand and pebbles can be separated using a filter, allowing smaller particles to pass through while retaining larger ones.

Jason wants to separate the ingredients in these mixtures. Which of the following should he use to separate the iron filings from the sand?

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Richard has four cups of water. In Cup 1, he adds some metal nails. In Cup 2, he adds a rubber ball. In Cup 3, he adds a spoonful of salt. In Cup 4, he adds a spoonful of grape drink powder. After 30 seconds of stirring, what will Cup 2 most likely look like?

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Tags

NGSS.MS-PS1-2

Which mixture is most likely to be separated with the help of a stove?

• Mixture 1

• Mixture 2

• Mixture 3

• Mixture 4

Answer explanation

Mixture 4 is most likely to be separated using a stove because it may involve components that can be heated to change states, such as separating liquids or solids through boiling or evaporation, which is not typical for the other mixtures.

Tags

NGSS.MS-PS1-4

A fruit salad and a bag of assorted nuts are examples of mixtures. What do all mixtures have in common?

• Mixtures are any type of matter that can change color when heated.

• Mixtures are any type of matter that can be shaken or stirred.

• Mixtures are a combination of two or more substances that can be changed into a solid or liquid.

• Mixtures are a combination of two or more substances that keep their own identities.

Answer explanation

All mixtures consist of two or more substances that retain their individual properties, meaning they do not chemically combine. This is why a fruit salad and a bag of assorted nuts maintain their distinct identities.

A student mixed powdered lemon juice mix with water to make a small amount of lemonade. The student left the lemonade in an open cup outside in the sun. After a few days, the student found the container and observed that changes had occurred to the mixture in the cup. What most likely happened to the mixture?

• The lemon juice mix evaporated, leaving only clear water in the cup.

• The liquid lemonade mixture was lighter in color after some water evaporated.

• The cup was empty after the mixture evaporated into the air.

• The water evaporated, leaving only a dry yellow solid in the cup.

Answer explanation

The water in the lemonade evaporated due to exposure to the sun, leaving behind the dry yellow solid from the lemon juice mix. This explains why the cup would contain only a dry substance after a few days.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Which of the following is an example of a mixture that maintains the physical properties of its substances?

• Lemonade made out of sugar, lemon, and water

• Slime made out of glue, borax, and water

• Salt and water mixture

• Vinegar and baking soda mixture

Answer explanation

The salt and water mixture is a physical combination where both substances retain their individual properties. In contrast, lemonade, slime, and the vinegar-baking soda mixture involve chemical changes or interactions that alter properties.

Which of the following is an example of a mixture that maintains the physical properties of its substances? 

Which statement supports your answer?

• A magnet can be used to separate the substances.

• Evaporation can be used to separate the substances.

• A wire mesh can be used to separate the substances.

• The mixture separates into distinct layers.

Answer explanation

Evaporation can separate substances in a mixture without changing their physical properties, indicating that the mixture retains the characteristics of its components.