Elements, Mixtures and compounds.

Question 1

What is an element?

Answer 1

An element is a pure substance that cannot be broken down into simpler substances by chemical means.

Question 2

True or False: A compound is made up of two or more different elements chemically bonded together.

Answer 2

True

Question 3

What is a mixture?

Answer 3

A mixture is a combination of two or more substances that are not chemically bonded.

Question 4

Fill in the blank: An example of a compound is ______.

Answer 4

water (H2O)

Question 5

What distinguishes a homogeneous mixture from a heterogeneous mixture?

Answer 5

A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture has distinct, separate components.

Question 6

Which of the following is an example of an element? A) Water B) Oxygen C) Salt

Answer 6

B) Oxygen

Question 7

True or False: All compounds are homogeneous mixtures.

Answer 7

True

Question 8

What is the chemical formula for table salt?

Answer 8

NaCl

Question 9

Fill in the blank: In a ______ mixture, the individual substances retain their own properties.

Answer 9

heterogeneous

Question 10

What are the two main types of mixtures?

Answer 10

Homogeneous and heterogeneous mixtures.

Question 11

Which of the following is a characteristic of compounds? A) Fixed composition B) Variable composition C) Can be separated by physical means

Answer 11

A) Fixed composition

Question 12

True or False: Mixtures can be separated by physical methods.

Answer 12

True

Question 13

What is the primary difference between elements and compounds?

Answer 13

Elements consist of only one type of atom, while compounds consist of two or more different types of atoms chemically bonded.

Question 14

Fill in the blank: The process of forming a compound from elements is called ______.

Answer 14

chemical bonding

Question 15

What is an example of a homogeneous mixture?

Answer 15

Saltwater

Question 16

Which of the following describes a physical change? A) Rusting of iron B) Dissolving sugar in water C) Burning wood

Answer 16

B) Dissolving sugar in water

Question 17

True or False: A chemical reaction occurs when elements combine to form a compound.

Answer 17

True

Question 18

What is the term for a substance made of only one type of atom?

Answer 18

Element

Question 19

Fill in the blank: A ______ mixture consists of visibly different substances or phases.

Answer 19

heterogeneous

Question 20

What is the smallest unit of a compound called?

Answer 20

Molecule

Question 21

Which of the following is an example of a heterogeneous mixture? A) Air B) Salad C) Sugar water

Answer 21

B) Salad

Question 22

True or False: Compounds can exist in any state of matter.

Answer 22

True

Question 23

What is the primary method to separate components of a homogeneous mixture?

Answer 23

Distillation

Question 24

Fill in the blank: The law of definite proportions states that a chemical compound contains the same ______ of elements by mass.

Answer 24

proportion

Question 25

What is the difference between a compound and a mixture?

Answer 25

A compound has a fixed composition and chemical bonds, while a mixture has variable composition and no chemical bonds.