Science Benchmark Review

Which term describes the substance that forms when 2 or more types of atoms are joined chemically?

• element

• compound

• composite

• mixture

Which shows one example of a physical change then one example of a chemical change?

• dissolving sugar and grinding paper

• melting butter and mixing flour with salt

• boiling water and burning gasoline

• roasting meat and freezing leftovers

Which is an example of a physical change?

• ice melting

• iron rusting

• wood burning

• garbage rotting

If a chemical reaction such as the formation of Iron Oxide contains 4 atoms of Iron (Fe) in the product, how many atoms of Iron (Fe) would be in the reactants?

• 12 atoms of Iron (Fe)

• 8 atoms of Iron (Fe)

• 4 atoms of Iron (Fe)

• 2 toms of Iron (Fe)

Which describes a characteristic of river basins?

• they are a source of groundwater

• they are saltwater ecosystems

• they flow down from aquifers

• they drain into the ocean

One dry summer, a large number of fish suddenly died in a shallow river. Which is the best explanation for this fish kill?

• the water became too warm to hold enough dissolved oxygen for the fish

• heavy rains washed soil into the river, making it too muddy for the fish

• fertilizer caused too many algae to grow and the fish died from overeating

• the water became too cold, stressing the fish so that they became sick and died

Which of these is most likely to have a harmful effect on water quality?

• having water and laws regulations

• using chemical indicators to check water quality

• treating sewage to kill pathogens

• letting pollutants wash out to sea

Think about how energy flows in this food web. Which organisms are found at the level with the most available energy?

• fox, snake, hawk

• cricket, caterpillar, rabbit

• shrew, songbird

• grasses

Which is the best example of a mixture?

• a brick of pure gold

• the distilled water in a bottle

• the salt water in the ocean

• the helium in a balloon

Which action causes a chemical change?

• boiling water

• crushing sugar cubes

• sifting flour

• cooking eggs