Holt Structure of Matter

What is the atomic mass of the element fluorine?

• 9

• 17

• 19.00

Tags

NGSS.MS-PS1-1

A Martian that has lived all of its life on Mars finally makes a trip to Earth. It has a hard time moving around, and that objects seem much heavier than on Mars. Why is this?

• Mars has less mass than Earth, which gives it less gravity, so objects weigh less on Mars.

• Mars has less mass than Earth, which gives it less gravity, so objects have less mass on Mars.

• The atmosphere is thicker on Earth than on Mars, which weighs down objects more and makes it harder to move them around.

Tags

NGSS.MS-PS2-4

Manganese (Mn) is a silver-colored metal. It reacts with oxygen to form manganese oxide (MnO₂), which has two oxygen atoms for every manganese atom. Which statement describes the properties of manganese oxide?

• It will be a gas because there are more oxygen atoms.

• Its properties will be different from manganese and oxygen because it will have some properties of each of the atoms that makes it up.

• Its properties will be different from manganese and oxygen because the properties depend on the type of atoms and how they are arranged.

Tags

NGSS.MS-PS1-1

The volume of each cube in the diagram is

125 cm³. The mass of each cube is also shown.

What can be concluded about the densities of the cubes?

• Cube A is twice as dense as Cube B.

• Cube B is twice as dense as Cube A.

• The density of the cubes cannot be compared because their weights are not given.

Tags

NGSS.MS-PS1-2

A molecule of ethane is made of two carbon (C) atoms and six hydrogen (H) atoms. The carbon atoms are joined by a chemical bond. Each of the hydrogen atoms is joined to one of the carbon atoms by a chemical bond. Which is an accurate model of ethane?

• 
• 
• 

Tags

NGSS.MS-PS1-1

A chemist wants to build a model of an element using a box. What should the box be filled with to show the relationship between atoms and elements?

• red marbles because an element is made up of atoms that all have the same properties

• an equal number of red and blue marbles because an element is made up of an equal ratio of atoms

• an equal number of red and blue marbles because bonds form between atoms that have different properties

Tags

NGSS.MS-PS1-1

Polyethylene is a flexible substance that is used in some plastic bags. The picture shows a model of polyethylene.

Why might polyethylene have properties that are useful for plastic bags?

• It is flexible because the hydrogen atoms are a gas that makes the structure flat.

• It is soft and flexible because it is made of carbon, which is hard and holds its shape as a crystal individually.

• It is soft and flexible because it is made of strands of carbon and hydrogen arranged for strength but that bend and slide past each other easily.

Tags

NGSS.HS-PS2-6

Anita made a frozen treat to eat on a hot day by pouring juice into an ice cube tray and putting the tray in the freezer. When she took it out of the freezer a few hours later, the juice was frozen.

When Anita took the tray out of the freezer, the frozen juice was made of the same substance as before because the types of atoms stayed the same. A __________ change occurred

• physical

• chemical

• nuclear

A jeweler has old gold jewelry that she wants make into new jewelry. She uses the process described below to separate the pure gold element from the impurities that are present in the old jewelry.

Step 1: A colorless strong acid is poured over the old gold jewelry. A process occurs that allows the gold to become dissolved in the acid. The impurities do not dissolve.

Step 2: After a while, the acid turns orange due to the pure gold particles dissolved in it. The acid/gold solution is poured into a separate container, leaving behind the impurities.

Step 3: The orange acid is then heated to evaporate the acid, and a chunky gold powder remains in the container.

Step 4: This gold powder is melted into liquid gold and poured into a mold to make a solid gold bar.

The substances involved in the process are all pure substances or mixtures. A mixture is a combination of substances in which the substances are not chemically combined. Mixtures are not pure substances.

Which is a pure substance?

• the old gold jewelery

• the acid/gold substance that was poured off in Step 2

• the gold dust at the end of Step 3

• solid gold in Step 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS1-5

Boron trioxide can form different structures. The picture shows two models of solid boron trioxide.

Which statements are correct?

• Model A is made up of molecules.

• Model B has a repeating structure.

• Both Model A and Model B show crystals.

Tags

NGSS.MS-PS1-1