Question

1. a chemical bond is

a. a group of atoms that are joined together.
b. the basic particle of matter.
c. the force that holds two atoms together.
d. a substance formed from the chemical combination of two or more atoms

1. which of the following is an example of a chemical change?

a. melting butter
b. mixing milk and chocolate syrup
c. breaking glass
d. burning leaves

1. which of the following is not true of atoms?

a. they are composed of molecules.
b. they combine to form compounds.
c. they make up elements.
d. they are extremely small.
completion
fill in the blank to complete each statement.

1. a(n) ____________ is a group of atoms that are joined together and act as a single unit.
2. an objects ____________ is its mass divided by its volume.
3. to find the volume of a rectangular solid, multiply the ____________ × width × height.
4. a pure substance that cannot be broken down into any other substances by chemical means is called a(n) ____________.
5. usable amounts of metal can be removed from a rock called a(n) ____________.

true or false
if the statement is true, write true. if it is false, change the underlined word or words to make the statement true.

1. during a chemical change, the form of a substance is altered, but not its identity.
2. dalton inferred that all atoms of an element are identical
3. electrolysis can be used to separate copper from its ore.
4. a solid block that sinks in a container of water has a lower density than water.
5. ice is an example of the liquid state of matter.

Explanation:

1. A chemical bond is the force holding two atoms together.
2. Burning leaves is a chemical change as it results in a new substance formation. Melting butter, mixing milk - chocolate syrup, and breaking glass are physical changes.
3. Atoms combine to form molecules and compounds, make up elements, and are extremely small. They are not composed of molecules.
4. A molecule is a group of atoms joined together and acting as a single unit.
5. An object's density is its mass divided by its volume.
6. To find the volume of a rectangular solid, multiply the length × width × height.
7. A pure substance that cannot be broken down into other substances by chemical means is called an element.
8. Usable amounts of metal can be removed from a rock called an ore.
9. False. During a chemical change, the identity of a substance is altered.
10. True. Dalton inferred that all atoms of an element are identical.
11. True. Electrolysis can be used to separate copper from its ore.
12. False. A solid block that sinks in a container of water has a higher density than water.
13. False. Ice is an example of the solid - state of water.

Answer:

1. c. the force that holds two atoms together.
2. d. burning leaves
3. a. They are composed of molecules.
4. molecule
5. density
6. length
7. element
8. ore
9. False. During a chemical change, the identity of a substance is altered.
10. True
11. True
12. False. A solid block that sinks in a container of water has a higher density than water.
13. False. Ice is an example of the solid - state of water.