Chapter 2

Question 1

Elements

Answer 1

are substances that cannot be broken down chemically into simpler substances.

Question 2

All elements can be found where?

Answer 2

Periodic Table

Question 3

How many elements make up the human body?

Answer 3

99.9%

Question 4

Big 4 elements

Answer 4

Oxygen, Carbon, Hydrogen, Nitrogen

Question 5

Atoms

Answer 5

smallest component of an element that cannot be subdivided further without loosing its properties

Question 6

Mass number

Answer 6

number of protons and neutrons in the nucleus.

Question 7

Atomic number

Answer 7

Number of protons in an atom

Question 8

Isotopes

Answer 8

atoms with the same number of protons, but a different number of neutrons

Question 9

radioactive isotopes

Answer 9

Isotopes that are not stable and emit radiation

Question 10

When are isotopes stable?

Answer 10

when it has a balanced number of neutrons or protons.

Question 11

Valence shell

Answer 11

Outermost shell with e-

Question 12

How many electrons can shell 1 have

Answer 12

2

Question 13

How many electrons can shell 2 have?

Answer 13

8

Question 14

How many electrons can shell 3 have?

Answer 14

8

Question 15

Inert

Answer 15

Non-reactive atoms, full atomic shells

Question 16

Reactive

Answer 16

Atoms that interact with other atoms, aren’t full

Question 17

Ions

Answer 17

Atoms with an electrical charge: positive or negative

Question 18

Positively charged ions

Answer 18

Cations

Question 19

Negatively charged ions

Answer 19

Anions

Question 20

How do chemical bonds allow atoms to achieve stability?

Answer 20

creating arrangements to fill the outer shell of each atom.

Question 21

Ionic Bond

Answer 21

Form when one or more electrons are transferred between atoms

Question 22

Covalent Bonds

Answer 22

Formed when electrons are shared between atoms

Question 23

Electrons transferred: One atom donates an e-

Answer 23

Gains a+ charge

Question 24

One atom accepts an e-

Answer 24

Gains a – charge

Question 25

Non polar covalent bonds

Answer 25

Equal sharing of electrons

Question 26

Polar covalent bonds

Answer 26

Unequal sharing of electrons

Question 27

Cohesion

Answer 27

water molecules' ability to interact with each other

Question 28

Adhesion

Answer 28

water molecules ability to interact with other molecules

Question 29

Water is referred to as the what solvent?

Answer 29

Universal solvent

Question 30

Acids

Answer 30

Compounds that release or donate H+ ions are called acids

Question 31

Bases

Answer 31

Compounds that releases OH- or combines with H+

Question 32

Buffers

Answer 32

compounds that resist changes of pH