Chemistry Test

Question 1

Element

Answer 1

A substance that can’t be broken down into simpler substances

Question 2

How many elements occur naturally?

Answer 2

92

Question 3

How many elements are essential to life?

Answer 3

25

Question 4

What are the 4 most abundant elements on earth from most to least? What are their percentages?

Answer 4

Oxygen- 65%
Carbon- 16.5%
Hydrogen- 9.5%
Nitrogen- 3.5%

Question 5

What is the smallest unit of an element that still has properties of that element?

Answer 5

Atom

Question 6

Define compound

Answer 6

Two or more elements chemically combined in a fixed ratio

Question 7

What are covalent bonds?

Answer 7

When 2 atoms share one or more pairs of electrons

Question 8

Give an example of a covalent bond

Answer 8

Water (is also polar)

Question 9

Life depends on what?

Answer 9

Chemistry

Question 10

What is an ionic bond?

Answer 10

When one atom loses an electron and the other atom gains an election

Question 11

Another way to think of an ionic bond

Answer 11

Think of it as tug of war, they’ll always share that electron

Question 12

What will an ionic bond form? Give an example

Answer 12

A crystal such as salt

Question 13

What is a hydrogen bond?

Answer 13

A chemical bond in which a hydrogen atom of one molecule is attracted to an electronegative atom, especially nitrogen, oxygen, or fluorine

Question 14

Give an example of a hydrogen bond

Answer 14

Water

Question 15

Which bonds break easily but also forms easily?

Answer 15

Hydrogen bonds

Question 16

List the 4 states of matter

Answer 16

• Solid
• Liquid
• Gas
• Plasma

Question 17

What’s activation energy?

Answer 17

The amount of energy required to start a chemical reaction

Question 18

Define solution

Answer 18

The solute in the solvant

Question 19

What would be the solute in koolaid?

Answer 19

The koolaid powder

Question 20

What would be the solvent in koolaid?

Answer 20

The water

Question 21

What’s a suspension?

Answer 21

When the substance floats in water but gradually sinks to the bottom

Question 22

Give an example of a suspension

Answer 22

Snowglobe

Question 23

What’s a colloid?

Answer 23

Particle substance that floats but never sinks or settles out

Question 24

Example of a colloid

Answer 24

Cherry jello in water

Question 25

Define cohesion

Answer 25

Attraction of water to water

Question 26

Define adhesion

Answer 26

The attraction of water to glass

Question 27

Define pH

Answer 27

The measure of how acidic or basic a substance is (0-14)

Question 28

Define acid

Answer 28

Less than 7. More H30+ (hydronium) ions

Question 29

Define base

Answer 29

Greater than 7. More OH- (hydroxide) ions.

Question 30

Define polar

Answer 30

When one side has a negative charge and the other side has a positive charge

Question 31

Buffer

Answer 31

Neutralizes the effect of adding small amounts of an acid or base to a solution