Chapter Two: Basic Chemistry

Question 1

Elements

Answer 1

A substance that cannot be broken down into simpler substances with different properties by ordinary chemical means

Question 2

Atoms

Answer 2

The smallest part of an element that displays the properties of the element

Question 3

Matter

Answer 3

Anything that take up space and has mass

Question 4

Atomic symbol

Answer 4

One or two letter which stand for elements

Question 5

Protons

Answer 5

Positive subatomic particle located in the nucleus and assigned one atomic mass unit

Question 6

Neutrons

Answer 6

Neutral subatomic particle located in the nucleus and assigned one atomic mass unit

Question 7

Electron

Answer 7

Negative subatomic particle, moving about in an energy level around the nucleus of an atom

Question 8

Electron she’ll

Answer 8

The average location or energy level of an electron in an atom. Often drawn as concentric circles around the nucleus

Question 9

Atomic number

Answer 9

Number of protons within the nucleus of atom

Question 10

Mass number

Answer 10

Mass of an atom equal to the number of protons plus the number of neutrons within the nucleus

Question 11

Atomic mass

Answer 11

Average of atom mass units for all the isotopes of an atom

Question 12

Isotopes

Answer 12

Atoms of the same element that differ in the number of neutrons

Question 13

Tracer

Answer 13

Detects molecular changes when a small amount of radioactive isotopes are added to a sample

Question 14

Octet Rule

Answer 14

The observation that an atom is most stable when it’s outer shell is complete and contains eight electrons

Question 15

Molecule

Answer 15

Exists when two or more elements bond together and is the smallest part of a compound that retains its chemical properties

Question 16

Compound

Answer 16

A molecule containing at least two different elements

Question 17

Formula

Answer 17

Tells the number of each kind of atom in a molecule

Question 18

Ions

Answer 18

Charged particle that carries a negative of positive charge

Question 19

Ionic bond

Answer 19

Chemical bond in which ions are attracted to one another by opposite charges

Question 20

Salts

Answer 20

Solid substances that usually separate and exist as individual ions in water

Question 21

Covalent bond

Answer 21

Results when two atoms share electrons in such a way that each atom has an octet of electrons in the outer shell

Question 22

Nonpolar covalent bond

Answer 22

When the sharing of electrons between two atoms is equal

Question 23

Electronegativity

Answer 23

Dependent on the number of protons- greater number of protons, greater electronegativity

Question 24

Polar covalent bond

Answer 24

When electrons are not shared equally in a covalent bond

Question 25

Hydrogen bond

Answer 25

A weak attraction between a slightly positive hydrogen atom and a slightly negative atom

Question 26

Calorie

Answer 26

The amount of heat energy needed to raise the temperature of 1 gram of water 1 degree Celsius

Question 27

Solution

Answer 27

Fluid that contains a dissolve liquid

Question 28

Solute

Answer 28

Substance that is dissolved in a solvent

Question 29

Hydrophilic

Answer 29

Molecules that do dissolve in water

Question 30

Hydrophobic

Answer 30

Molecules that do not dissolve in water

Question 31

Surface tension

Answer 31

Strong force between molecules in a liquid

Question 32

Hydrogen ions

Answer 32

Hydrogen atom that has lost its electron and therefore has a positive charge

Question 33

Hydroxide ions

Answer 33

One of two ions that results when a water molecule dissociates; gained an electron and therefore beard a negative charge

Question 34

Acids

Answer 34

Molecules tending to raise the hydrogen ion concentration in a solution and thus to lower its pH numerically

Question 35

Bases

Answer 35

Molecules tending to lower the hydrogen ion concentration in a solution and this raise the pH numerically

Question 36

PH scale

Answer 36

Measurement scale for hydrogen in concentration

Question 37

Buffer

Answer 37

Substance or group of substances that tend to resist pH changes of a solution, this stabilizing its relative acidity and basicity

Question 38

What 6 elements make up 95% of the body weight of organisms

Answer 38

``` Hydrogen Nitrogen Carbon Oxygen Calcium Phosphorus ```

Question 39

All isotopes have the same number of...

Answer 39

Protons

Question 40

What type of bond is formed when atoms share electrons

Answer 40

Covalent

Question 41

The three isotopes of carbon have different numbers of...

Answer 41

Neutrons

Question 42

Which bond is most easily broken?

Answer 42

Hydrogen bond

Question 43

Normal rainfall has a pH of...

Answer 43

8.3

Question 44

Hydrophobic molecules tend to be...

Answer 44

Nonpolar

Question 45

5 properties of water

Answer 45

``` High heat capacity High heat of evaporation Solvent Cohesive and Adhesive Ice is less dense than liquid water ```

Question 46

Alkaline

Answer 46

Blood at a pH level of 7.4 (slightly basic)

Question 47

Atom in Greek means...

Answer 47

Uncut or indivisible

Question 48

The atom most commonly found in the human body is...

Answer 48

Oxygen