P 1.3

As part of a science experiment, Jose did a test for starch on a slice of apple and a slice of a potato. The yellow orange iodine solution stayed the same color when it was put on the apple, but it became black on the potato

Which is the best example as to why the iodine solution changed on the potato?

• The iodine mixed with the colors of the potato so it looked black

• The iodine reacted with the potato to form a new substance

• The iodine burned the potato and it turned to ash

• The iodine evaporated into gas

Tags

NGSS.MS-PS1-2

Physical changes in water are often cause by ________

• oxidation

• combustion

• chemical reactions

• temperature

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A pure liquid substance is held over a heat source slowly it evaporates into a gas which is captured in a balloon.

Which example best explains the gaseous substance and liquid substance?

• They both have the same composition

• have different compositions

• have the same volumes

• have the same masses

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-1

A science teacher mixed room temperature samples of hydrochloric acid and sodium hydroxide in a beaker. The solution still looked like water but when students touched the beaker it was warm.

What is the best explanation for this?

• The energy of mixing warmed the solution

• The 2 liquids were not soluble to water

• The chemical reaction was creating a new susbtance

• The release of gas heated the solution

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

NGSS.MS-PS1-4

When a small piece of white marble rock is carefully placed in a beaker of hydrochloric acid, bubbles form on the surface of the rock and rise to the top of the liquid.

Which conclusion best fits the observation?

• The rock reacted with the acid and made a new gaseous substance

• The rock heated with the acid until it began to boil

• Nothing changed

• The rock dissolved in the cold by breaking into small pieces

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The chemical equation above describes a chemical reaction.

Which of the following statements about the chemical equation is true?

• Iron oxide is a mixture of iron and oxygen.

• Iron and aluminum oxide react to form iron and aluminum.

• Iron and iron oxide react to form aluminum.

• Iron is a pure substance with different properties than iron oxide.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following represents the chemical reaction of benzene and nitric acid to produce nitrobenzene and water?

• nitrobenzene + nitric acid → benzene + water

• benzene + nitric acid → nitrobenzene + water

• nitrobenzene + water → benzene + nitric acid

• water + benzene → nitrobenzene + nitric acid

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The _______ are found on the left side of the arrow in a chemical reaction and the ________ are found on the right side of the arrow.

• factors; coefficients

• products;reactants

• reactants;products

• products; factors

Jenny places a strip of pH paper into a solution. When she removes the pH paper, it has turned yellow-green.

What should Jenny do next to determine the pH of her solution?

• compare the pH paper's color with a chart of colors and pH ranges

• compare the pH paper's color with the color of pH paper from another solution

• place the pH paper into a machine that reads the pH of the solution

• use a different testing method because the pH paper should not change colors

A chemical equation is a way of describing how

• a mixture of substances change to produce one or more mixtures with the same properties as the original substances.

• pure substances change to produce one or more pure substances with different properties from the original substances.

• pure substances are combined into a mixture that has the same properties as the original substances.

• a mixture of substances are separated into two or more pure substances that do not react with each other.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5