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

NGSS.MS-PS1-2

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.

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 model an element using a box filled with marbles. What should the box be filled with to show the relationship between atoms and elements?

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

• 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

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

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

Which model is a repeating structure?

• Model A

• Model B

• Both Model A and Model B

• Neither Model A or Model B

Bill has iron flakes, salt, and water. He puts some of the iron and salt together in a cup and mixes them. Bill makes a table to describe some of the different substances he has.

Which substance is not made of molecules or compounds?

• Iron (Fe)

• Water (H₂O)

• Iron and Salt mixture

• Salt

Tags

NGSS.MS-PS1-1

The picture shows that a key is placed into a graduated cylinder filled with water.

Calculate the volume of the key.

• 25

• 30.5

• 5.5

• 3