Chapter 2- Chemistry

Question 1

What is matter composed of?

Answer 1

atoms

Question 2

Why do atoms combine?

Answer 2

To form compounds and molecules

Question 3

How do atoms interact?

Answer 3

Through electrons

Question 4

Strength of molecular interactions

Answer 4

Can be either strong or weak

Question 5

What fundamental substances is the natural world composed of?

Answer 5

Elements

Question 6

substances that can’t be broken down by a chemical reaction

Answer 6

Elements

Question 7

How are elements identified on period table?

Answer 7

Chemical symbols

Question 8

What elements make up ~96% of matter in organisms?

Answer 8

-Oxygen
-Carbon
-Hydrogen
-Nitrogen

Question 9

What are compounds made of?

Answer 9

Compounds contain 2+ different elements

Question 10

What contains

-Protons
-Electrons
-Neutrons

Answer 10

Atoms

Question 11

Protons are?

Answer 11

Positive charge

Question 12

Neutrons are?

Answer 12

neutral, no charge

Question 13

Electrons are?

Answer 13

negative charge

Question 14

How are elements identified by?

Answer 14

the number of protons in an atom

Question 15

What is the atomic number?

Answer 15

Number of protons

Question 16

What charge are atoms overall?

Answer 16

They are neutral, no charge

Question 17

What does the number of electrons equal to?

Answer 17

Usually equals the number of protons

Question 18

Where are electrons found?

Answer 18

In the shells

Question 19

How many electrons go in shell 1?

Answer 19

2

Question 20

How many electrons in shell 2?

Answer 20

8

Question 21

How many electrons in shell 3?

Answer 21

8

Question 22

What happens to the energy the closer electrons get to the nucleus?

Answer 22

The energy lowers

Question 23

Where do all chemical interactions in atoms occur?

Answer 23

Between electrons ONLY
(nuclei never interact)

Question 24

Even though protons are the same, electrons are

Answer 24

NOT the same
(variable amounts of energy)

Question 25

What is the outer electron shell called?

Answer 25

Valence shell

Question 26

What are the electrons in the valence shell called?

Answer 26

valence electrons

Question 27

When are atoms most stable?

Answer 27

When the valence shell is full

Question 28

Attractions are the result of what?

Answer 28

interactions between valence electrons of 2+ atoms

Question 29

The strength of chemicals bonds can be?

Answer 29

strong or weak

Question 30

extremely strong and stable bonds

Answer 30

Covalent bonds

Question 31

When do covalent bonds occur?

Answer 31

when adjacent atoms share electrons

Question 32

When 2 or more atoms are held together by covalent bonds

Answer 32

Molecule

Question 33

Why are atoms "bullies"?

Answer 33

They don't always share their electrons equally

Question 34

measure of how nucleus holds onto electrons

Answer 34

EN

Question 35

The more EN

Answer 35

the more strongly it pulls electrons

Question 36

Which are the most EN atoms of biological importance?

Answer 36

Oxygen and Nitrogen

Question 37

electrons are shared equally and charge are distributed symmetrically

Answer 37

Nonpolar covalent bond

Question 38

Unequal electron sharing and asymmetric distribution of electron charges

Answer 38

Polar covalent bonds

Question 39

What do weak bonds result from?

Answer 39

electrostatic attractions between two atoms

Question 39

Types of Weak bonds

Answer 39

-Hydrogen bonds -Ionic bonds -van deer Waal interaction

Question 40

-Extremely important in biological systems -occurs when H covalently bonded to one EN attracted to another EN atom

Answer 40

hydrogen bonds

Question 41

large EN differences pull electrons from the outer shell of one atoms

Answer 41

Ionic bonds

Question 42

atoms with electrical charge (positive or negative)

Answer 42

Ions

Question 43

How do atoms become ions?

Answer 43

gaining or losing electrons

Question 44

attractions between molecules that are close together as result of temporary changes (extremely weak)

Answer 44

Van der Waals interaction

Question 45

What do van der Waals interactions determine?

Answer 45

-3D shape of proteins -Specific interactions of antigens and antibodies -Specific interactions between enzymes and substrate

Question 46

Van der Waals: If electrons are not evenly distributed

Answer 46

They may accumulate by chance in one part of the molecule