Unit 24 Section 2 Study Guide

Josh is designing a lab to separate a mixture of sulfur powder and iron filings. He looks at all the ways to separate a mixture but decides that one way would work the best on this mixture. What method should Josh use?

• density

• filtration

• magnetic attraction

Answer explanation

The answer for the best method to separate this mixture is magnetic attraction. The sulfur and iron mixture can be separated with a magnet because iron has magnetic properties while sulfur does not.

Josh is designing a lab to separate a mixture of gravel, rocks, and sand. He looks at all the ways to separate a mixture but decides that one way would work the best on this mixture. What method should Josh use?

• density

• sifting

• magnet attraction

Answer explanation

The answer for the best method to separate this mixture is sifting. Josh will be able to separate the mixture by particle size using sieves with different size openings.

Salt water, a mixture, is made by dissolving salt in water. Mixtures like this can be separated by using the physical properties of the parts of the mixture. Which would be the best way to separate a mixture made of salt and water?

• evaporation

• filtration

• magnetism

Answer explanation

You can separate the water from the salt by evaporation. Heating the mixture will cause the water to evaporate, leaving the salt behind in the container.

What physical property would you use to separate these jelly beans?

• color

• mass

• texture

Answer explanation

The physical property of color is being used to separate these jelly beans.

Tags

NGSS.5-PS1-3

You need to separate a mixture of iron filings, sand, and salt. Which of the three components of the mixture would be easiest to separate first and what method would be best?

• The salt would be easiest to separate, and using a magnet would be the best method.

• The iron filings would be easiest to separate, and using a magnet would be the best method.

• The sand would be easiest to separate, and using hot water to dissolve the other substances would be the best method.

Answer explanation

The iron filings would be easiest to separate, and using a magnet would be the best method.

Which of these is the best evidence that matter is made of particles that take up space, even though they are too small to be seen?

• cracking an egg

• blowing up a balloon

• freezing a bottle of water

Answer explanation

The balloon will expand because air is taking up space inside even though you cannot see the air inside.

What is the name of this method, shown in the image, used to separate certain mixtures, like sugar and water?

• evaporation

• floatation

• sifting

Answer explanation

When the water begins to boil, it will evaporate, leaving the solid portion of the mixture behind.

Tags

NGSS.MS-PS1-4

Filtration, or screening, is one way to separate certain mixtures, as shown in the image. Which of these mixtures could be most easily separated by filtration?

• oil and water

• dissolved sugar and water

• flour and marbles

Answer explanation

flour and marbles Smaller particles (flour) fall through the screen or filter leaving behind the larger particles.

Jose has a sore throat. His mother pours warm water in a glass, and adds 2 tablespoons of salt. At first Jose notices the salt on the bottom of the glass, but as his mother mixes it, the salt seems to disappear. What happened to the salt in the glass?

• The water and salt turn into a solid form of matter.

• The salt evaporated because of the temperature of the water.

• The water dissolved the salt into smaller particles that cannot be seen.

Answer explanation

The water dissolved the salt into smaller particles that cannot be seen.

The water breaks apart the salt into ions. The ions bind with the atoms that make up water.

Tags

NGSS.MS-PS1-2

Which is an example of a mixture made of parts that can easily be separated?

• cake (flour, eggs, sugar)

• water (hydrogen and oxygen)

• snack mix (nuts, pretzels, and chips)

Answer explanation

Snack mix (nuts, pretzels, and chips) are easy to separate. You can pick out the pieces with your fingers. The other three substances cannot be separated into their parts very easily.