Matter and Chemical Reactions

Read the List.

AIR

Ballon

Bowl of Cereal

Oil and water mixture

Which of example from the list is a homogeneous mixture?

​ (a)  

• The Balloon- helium atoms are not uniform
• The Oil and water- mixed evenly
• The Bowl of Cereal-is not uniform
• Air-contains several gases, they are uniform

1. Paula is a scientist. She wants to identify whether a mixture is homogeneous or heterogeneous. While she is able to separate the elements of the substance, she is not able to see the elements on their own. Therefore, the mixture is homogeneous.

Which of the following examples could be the mixture she is separating?

• Saltwater

• Bowl of Cereal

• Orange juice with pulp

• Water with ice

Maria is at the beach and gets sand in her water bottle. Her friend tells her not to worry, as she can separate the sand out easily. Which of the following describes why this mixture can be separated?

• 1. Sand and water are different substances with similar properties which can be used to separate them from each other.

• 1. The properties of sand and water change when they are mixed together.

• 1. Sand and water form a new substance when they mix, so they can be separated based on their new properties.

• The properties of sand and water do not change when they are mixed, so they can be separated from each other without the substance changing.

Lionel is making some lemonade. He adds sugar into a glass of water and stirs. After he stirs, he can no longer see the sugar. Lionel wonders if a new compound has been made. Which statement describes what happens to the sugar and water?

• The sugar molecules disappear when added to the water and are no longer in the glass.

• 1. The water and sugar form a mixture that does not change the water molecules but does change the sugar molecules, resulting in a new substance.

• The water and sugar form a mixture that does not chemically change the water molecules or the sugar molecules.

• 1. The water and sugar molecules bond together to form a new, larger molecule.

1. Look at the picture containing models of different types of matter.

• O2 and CH4

• 1. Only CH4

• O2 and Fe

• 1. Only Fe

Tags

NGSS.MS-PS1-1

A group of students are conducting an investigation involving two different substances. When the two substances are mixed together, bubbles form.

Based on the information, did a physical change or a chemical change occur?

• 1. A physical change occurred because bubbles were produced.

• 1. No change occurred because the matter is still liquid.

• A chemical change occurred because a gas was produced.

• 1. No change occurred because the substances did not react.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

1. Kami notices her toast is burned after being in the toaster oven for too long. Kami wonders if a chemical change has occurred in the burned toast.

Which observation would indicate a chemical change occurred?

• The temperature of the toast is very hot from the toaster.

• The color of the toast changes to a darker color.

• The color of the toast does not change.

• 1. The shape of the toast changes.

Tags

NGSS.MS-PS1-2

1. Every molecule is represented with a formula. Formulas are made up of different numbers of atoms.

Choose the answer that lists the chemical formulas in order from least to greatest number of atoms.

• NBr3, C3H8, H2SO4, CH3COOH

• NBr3, H2SO4, CH3COOH, C3H8

• NBr3, H2SO4, C3H8, CH3COOH

• 1. C3H8, CH3COOH, H2SO4, NBr3

Tags

NGSS.MS-PS1-1

1. Which statement best explains the difference between a physical change and a chemical change?

• A physical change involves a change in the color and shape of a substance; a chemical change involves a change in the temperature and texture of a substance.

• 1. A physical change involves a change in the color of a substance; a chemical change involves a change in the shape of a substance.

• 1. A physical change involves the formation of a new substance; a chemical change involves a change in the appearance of a substance without forming a new substance.

• A physical change involves a change in the appearance or form of a substance without forming a new substance; a chemical change involves the formation of a new substance.

1. Maria is investigating various compounds. She has the chemical formulas for each compound.

What does the chemical formula help her know about each substance?

• 1. The chemical formula tells her that there has been production of a gas.

• The chemical formula tells her that the compound underwent a color change.

• The chemical formula tells her the type and number of atoms in the compound.

• The chemical formula tells her the weight of each compound.

Tags

NGSS.MS-PS1-1