Assessment: Elemental Changes, Compounds, Equations, and Such

When a substance undergoes a physical change, what remains unchanged?

• the physical appearance

• the composition

• the state of matter

• the temperature

What happens to the atoms in a substance during a chemical change?

• They are rearranged to form new molecules.

• They are destroyed.

• They remain in the same arrangement.

• They move farther apart without changing structure.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

When water boils, it turns into steam. This is an example of:

• a physical change because the composition of water remains the same

• a chemical change because steam is a different substance

• both a physical and chemical change

• neither a physical nor chemical change

Tags

NGSS.MS-PS1-4

Which statement best explains why a precipitate forms when two solutions are mixed?

• A physical change occurs where solids are produced.

• The solutions undergo a phase change.

• The solutions combine to form a new mixture.

• A chemical change occurs, resulting in a new substance.

Tags

NGSS.MS-PS1-2

Your teacher presents a demonstration showing the reaction between lemon juice and baking soda. You observe a beaker with lemon juice and baking soda mixing, producing bubbles and releasing gas. A temperature sensor shows a slight decrease in temperature. Below the diagram, there is a table listing observations and measurements taken during the experiment. Two of your classmates, Olivia and Jackson, discuss what is happening in the experiment: Olivia: "The observations indicate a physical change." Jackson: "I believe a chemical change has occurred." Which student is correct?

• Olivia

• Jackson

• Both students are correct.

• Neither student is correct.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Which explanation best supports your choice between Olivia and Jackson?

• Gas production and temperature change are signs of a physical change where no new substances are formed.

• Physical changes always involve temperature change and gas production.

• The production of gas and the increase in temperature are indications of a chemical change where new substances are formed.

• Chemical changes never involve gas production or temperature change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

The periodic table is organized into three main categories. Which of the following correctly identifies these categories?

• solids, liquids, and gases

• metals, nonmetals, and metalloids

• elements, compounds, and mixtures

• natural, synthetic, and alloys

What does the subscript '3' in the chemical formula Al₂O₃ indicate?

• There are 3 aluminum atoms in the molecule.

• There are 3 oxygen atoms in the molecule.

• There are 3 molecules of aluminum oxide.

• There are 3 atoms of both aluminum and oxygen in the molecule.

Tags

NGSS.MS-PS1-1

Which of the following formulas represents a compound with 1 calcium atom and 2 chlorine atoms?

• CaCl

• Ca₂Cl

• CaCl₂

• Ca₂Cl₂

Tags

NGSS.MS-PS1-1

Which of the following best describes the formula CaCO₃?

• 1 calcium, 1 carbon, 3 oxygen

• 1 calcium, 3 carbon, 3 oxygen

• 3 calcium, 1 carbon, 1 oxygen

• 3 calcium, 3 carbon, 1 oxygen

Tags

NGSS.MS-PS1-1