Chemistry Unit 2 Test: The Atom

Question 1

the smallest unit of an element that still has the properties of that element

Answer 1

atom

Question 2

the positive subatomic particle in the nucleus of an atom

Answer 2

proton

Question 3

the neutral subatomic particle in the nucleus of an atom

Answer 3

neutron

Question 4

the negative subatomic particle in the electron cloud of an atom

Answer 4

electron

Question 5

electrons in the outermost energy level of the electron cloud

Answer 5

valence electrons

Question 6

make up protons and neutrons and their attraction holds the nucleus together

Answer 6

quarks

Question 7

the atom is positively charged with negatively charged particles embedded throughout

Answer 7

plum pudding model

Question 8

the center of the atom (nucleus) is positive and the negative parts surrounds it

Answer 8

nuclear model

Question 9

the plum pudding model represents

Answer 9

an important step in the development in atomic theory; not only did it incorporate new discoveries, such as the existence of the electron, it also introduced the notion of the atom as a non-inert, divisible mass

Question 10

the nuclear model was

Answer 10

the first step toward our modern understanding of the atom

Question 11

e- (electrons) travel in fixed orbits around the nucleus

Answer 11

Bohr model

Question 12

e- (electron) are in shells in the cloud but do NOT travel in fixed orbits

Answer 12

Electron cloud model

Question 13

Be able to differentiate between the Plum Pudding Model and the __________________

Answer 13

Nuclear Model

Question 14

Be able to differentiate between the Bohr Model and the _________________

Answer 14

Electron Cloud Model

Question 15

Explain the structure of the electron cloud: (3 points)

Answer 15

1) Divided into shells/energy levels
2) Electrons in the shell closest to the nucleus have the least amount of energy (holds a max of 2 electrons)
3) Electrons in the shell farthest from the nucleus have the most energy (and these outermost electrons are called valence electrons)

Question 16

Describe the forces that hold the atom together: (2 points)

Answer 16

1) There is an attractive electromagnetic force between the positive nucleus and the negative electron cloud.
2) There is also the strong nuclear force between the quarks in the nucleus that holds it together despite the repulsive electromagnetic force between the positive protons.

Question 17

number of protons in an atom of the element; used to identify an element

Answer 17

atomic number

Question 18

number of protons and neutrons in the nucleus of an atom

Answer 18

mass number

Question 19

AKA families

Answer 19

groups

Question 20

the vertical columns on the periodic table

Answer 20

groups

Question 21

Groups have what in common?

Answer 21

number of valence electrons

Question 22

Periods have what in common?

Answer 22

energy levels

Question 23

the horizontal rows on the periodic table

Answer 23

periods

Question 24

atoms of the same elements with different numbers of neutrons

Answer 24

isotopes

Question 25

a charged atom

Answer 25

ion

Question 26

weighted average of all of the different versions of an element; measured in amu

Answer 26

average atomic mass

Question 27

described the pattern/shared characteristics that elements in the same group share versus elements in the same period

Answer 27

Elements in the same group have the same number of valence electrons.
Elements in the same period have the same number of energy levels in their electron clouds.

Question 28

Explain why elements in the same group often have similar properties. Then list any names and special characteristics that define these groups.

Answer 28

Elements in the same group often have similar properties because they have the same number of valence electrons and thus, have similar bonding patterns.

Question 29

Group 1 on the periodic table:

Answer 29

Alkali metals - most reactive metals

Question 30

Group 2 on the periodic table:

Answer 30

Alkaline earth metals

Question 31

Group 3 on the periodic table:

Answer 31

rare earth metals

Question 32

Groups 3-12 on the periodic table:

Answer 32

Transition metals

Question 33

Group 17 on the periodic table:

Answer 33

Halogens - most reactive nonmetals

Question 34

Group 18 on the periodic table:

Answer 34

Noble gases - nonreactive

Question 35

Which group contains the most reactive metals and what are they called?

Answer 35

Group 1, Alkali metals

Question 36

Which group contains the most reactive nonmetals and what are they called?

Answer 36

Group 17, Halogens

Question 37

Which group contains the least reactive and why?

Answer 37

Group 18 - this is because they have a full valence electron shell, making them chemically stable

Question 38

Metals:

Answer 38

left of metalloids, usually solids, good conductors

Question 39

Nonmetals:

Answer 39

right of metalloids, (except Hydrogen), usually gases or dull and brittle solids, poor conductors

Question 40

Metalloids:

Answer 40

B, Si, Ge, As, Sb, Te, solids, semi-conductors, physical properties like metals chemical properties like nonmetals

Question 41

Give an example of hyphen and nuclear notation for the most common isotope of Hydrogen. Explain what the notation tells you about the atom.

Answer 41

Hydrogen - 1
1(subscript)H
The notation tells you the identity of the atom and its mass number. It can also notate if the atom has a charge or is electrically neutral.

Question 42

Explain what it means for an atom to be electrically neutral, and include the name for an atom that is NOT electrically neutral.

Answer 42

An electrically neutral atom has an equal amount of positive protons and negative electrons, and therefore has an overall charge of 0.
An atom that is NOT electrically neutral has an imbalance of p+ and e- and thus has a charge. This is known as an ion.