Chapter 2

Question 1

Element

Answer 1

• 1 atom
• cannot be broken down further

Question 2

Compound

Answer 2

• 2 or more elements in fixed ratio
• emergent properties, characteristics different form other elements

Question 3

Elements Essential for Life

Answer 3

CHON(PS)
- Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur
(CHON) is 96% of elements required

Question 4

Trace Elements

Answer 4

required in minute quantities

Question 5

Atom

Answer 5

smallest unit of matter that still retains properties of an element

Question 6

Neutron

Answer 6

• no charge, has mass

Question 7

Protons

Answer 7

-positive charge

Question 8

Electrons

Answer 8

negative charge

Question 9

Atomic Number is equal to the number of

Answer 9

protons

Question 10

Mass number is made up of

Answer 10

protons + neutrons

Question 11

Atomic mass

Answer 11

total approximated mass
- in diagram number on bottom left

Question 12

Isotopes

Answer 12

2 atomic forms of an element that have different numbers of neutrons

Question 13

Radioactive Isotopes

Answer 13

decay spontaneously and give off particles and energy

Question 14

Octet Rule

Answer 14

an atoms valence shell if full when it has 8 electrons, except for the innermost shell which is full with 2 electrons

Question 15

First shell has the …. energy and the third shell has the …. energy

Answer 15

• lowest
• highest

Question 16

A full shell means it is

Answer 16

not reactive and is stable

Question 17

Carbon can bond in … places to fill shell

Answer 17

four

Question 18

Covalent Bond

Answer 18

chemical bond formed by sharing electron pairs between two atoms

Question 19

Nonpolar Covalent Bond

Answer 19

• electrons shared equally between two atoms

Question 20

Polar Covalent Bond

Answer 20

• electrons are not shared equally between two atoms

Question 21

Ionic Bond

Answer 21

attraction between an anion and a cation

Question 22

Hydrogen Bond

Answer 22

attraction between two atoms already participating in other chemical bonds
- hold 2 or more water molecules together

Question 23

All chemical reactions are

Answer 23

reversible

Question 24

Chemical Equilibrium

Answer 24

reached when the forward and reverse reaction rates are equal

Question 25

Four Emergent Properties of Water

Answer 25

• cohesive behavior
• expansion upon freezing
• ability to moderate temperature
• versatility as solvent

Question 26

Adhesion

Answer 26

clinging of one substance to another

Question 27

Surface Tension

Answer 27

how hard it is to break surface of a liquid, related to cohesion

Question 28

Buffers

Answer 28

prevent from becoming too acidic or too basic