Matter

Salt and water are stirred together in a beaker. The solid salt particles seem to disappear in the water. Which is the best explanation for the product that is formed?

• A solvent has been created.

• A solution has been created.

• A compound has been created.

• A new element has been created.

Which of the following results when hydrogen and chlorine chemically bond to form hydrogen chloride?

• a mixture

• a solution

• a compound

• a precipitate

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

A student passes a magnet over 10 grams of a powder. Four grams of the powder stick to the magnet, while 6 grams do not. Which of these identifies the substance?

• element

• compound

• mixture

• solvent

A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buzzing sound as gas bubbles were forming around it. Which conclusion is BEST supported by this observation?

• A chemical change took place

• The lithium was dissolved by the water

• Dissolved gasses were released

• Water was vaporized

Tags

NGSS.MS-PS1-2

Match the following

• element

• a combination of two or more different elements bonded together

• atom

• a substance that consists of just one type of atom

• Compound

• anything that has mass and takes up space

• matter

• a small particle that is a building block of matter

Tags

NGSS.MS-PS1-1

One particle of table salt (NaCl) is best described as a (a)   .

• atom

• compound

• element

• mixture

Answer explanation

Table salt (NaCl) is a compound because it is made up of two different elements, sodium (Na) and chlorine (Cl), chemically bonded together.

Tags

NGSS.MS-PS1-1

A beaker contains a sample of water with a mass of 325 grams. The water in the beaker is boiled and weighed again after it cools. The new mass of the water is 305 grams. In this example of the conservation of matter in physical changes,

• the mass is less after it cools because water has less mass as a gas.

• the mass of the water was 305 grams and the mass of the water vapor was 20 grams.

• the process of boiling destroyed 20 grams of the water and left 305 grams of water.

• the heat energy created by boiling water makes up the rest of the mass.

Tags

NGSS.MS-PS1-5

Which is the BEST evidence that a chemical change has occurred?

• change of state

• release of energy

• temperature change

• formation of a new substance

Tags

NGSS.MS-PS1-2

During photosynthesis, carbon dioxide and water combine according to the general equation. Why is photosynthesis a chemical reaction?

• because new substances are formed

• because an input of energy is required

• because the reactants are compounds

• because the products include an element

Tags

NGSS.MS-LS1-6

NGSS.MS-LS1-7

Which statement BEST describes the change to an ice cube as it melts?

• The change is physical because the mass remains the same.

• The change is physical because the substance remains the same.

• The change is chemical because water has a different pH than ice.

• The change is chemical because ice has a lower density than water.

Tags

NGSS.MS-PS1-4