Sc.8.P.8.9

Sean stirred 10 grams of sand into 50 mL of water and 10 grams of salt into 50 mL of water, the he let both mixtures sit for 10 minutes. Which of the following differences did Sean observe between these two mixtures?

• The salt, sand, and water do not mix together.

• Salt dissolves in the water, but sand does not.

• Mixture 2 can be separated, but Mixture 1 cannot.

• Mixture 1 is a solid and a liquid, but Mixture 2 is not.

Tags

NGSS.MS-PS1-2

Melanie is given an unknown substance by her teacher. Melanie’s teacher tells her that the substance has a bitter taste. Melanie also observes that the substance is slippery. These properties indicate that the substance may be which of the following?

• Acid

• Salt

• Water

• Base

While elements and compounds are related, they are different. Unlike elements, which of the following describes a compound?

• Consists of only one type of atom

• Is the smallest form of a particle

• Always exists in the gas state of matter

• Is made of at least two types of matter

Acids and bases are compounds with very different properties. Which of the following is a property of an acid as opposed to a base?

• Reacts with most metals

• Has a pH above 7

• Feels slippery

• Is soluble in water

Provided is a table of five different substances. How many of these substances are pure substances?

• 2

• 3

• 4

• 5

Kathy is doing an investigation in science class, and she needs to use a base. Kathy can identify a base by finding a substance with which of the following properties?

• Reacts with most metals

• Tastes sour

• Has a pH above 7

• Is safe for humans to drink

Pure substances include elements and compounds. Which of the following describes an element as compared to a compound?

• Simplest form of matter

• Mixture of an acid and base

• A solution with a solute

• Made of more than one kind of atom

Alex tested a substance that has a pH of 2. Which of the following could Alex have tested?

• Base

• Salt

• Water

• Acid

Provided is a table of five different substances. How many of these substances are mixtures?

• 1

• 2

• 3

• 4

Leah records observations on an unknown substance. An image is provided. Based on Leah's observations, she can conclude that the unknown substance is which of the following

• Salt

• Base

• Water

• Acid