NGSS Grade 8 Science

Which of the following correctly pairs a phase of matter (like solids, liquids, and gases) with its correct description?

• Gas particles have no motion.

• Liquid: particles expand to fill the container they are placed in.

• Solid: particles have the highest amount of movement.

Which is an example of a pure substance?

• milk

• chocolate

• gold

• cactus

How can a scientist, using the Periodic Table, find an element with properties similar to another element?

• by comparing density

• by finding its periodic group

• by comparing malleability

• by comparing atomic mass

Which statement best explains how periods are organized on the periodic table?

• Increasing atomic number from left to right

• Increasing number of neutrons from left to right

• decreasing number of neutrons from left to right

• decreasing number of electrons from left to right

In the current model of the Periodic Table of Elements, the elements have been placed in groups or families, why?

• Elements in each group have similar densities

• Elements in each group have similar boiling points

• Elements in each group have similar melting points

• Elements in each group have similar physical and chemical properties

Why is salt water considered a mixture?

• It is composed (made up of) one element

• It is composed (made up of) of one compound

• It is composed (made up of) two or more compounds that have new properties

• It is composed (made up of) two or more substances that are not chemically combined

Which best explains why the total mass of the products would weigh less than the reactants after a chemical reaction?

• Gases are released to the atmosphere

• a physical change occured

• mass was lost in the atoms

• precipitates were created

Tags

NGSS.MS-PS1-5

If a chemical reaction like photosynthesis starts with 6 atoms of carbon, how many atoms of carbon should be in the product?

• 2 atoms of carbon

• 6 atoms of carbon

• 12 atoms of carbon

• 3 atoms of carbon

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5