Gen Chem 1

Question 1

What consists of an atom’s nucleus?

Answer 1

• protons
• neutrons

Question 2

protons

Answer 2

• the atomic number of an element is equal to the number of protons
• 1 amu
• denoted as “+1 e” or “+1”

Question 3

atomic number (Z)

Answer 3

• acts as a unique identifier for each element because elements are defined by the number of protons they contain

Question 4

neutrons

Answer 4

• have no charge
• together with protons, almost makes up entire mass of atom

Question 5

mass number (A)

Answer 5

sum of the protons and neutrons in the atom’s nucleus

Question 6

isotope

Answer 6

atoms that share an atomic number but have different mass numbers

Question 7

electrons

Answer 7

• move through space surrounding nucleus
• associated with varying levels of energy
• denoted as “-1 e” or “-1”

Question 8

Do the electrons closer to the nucleus have lower or higher energy levels?

Answer 8

have lower energy levels

Question 9

valence electrons

Answer 9

electrons that are farthest from the nucleus have the strongest interactions with the environment and the weakest interactions with the nucleus
- much more likely to become involved in bonds with other atoms

Question 10

Atomic mass and mass number are synonymous

Answer 10

True

Question 11

atomic weight

Answer 11

• constant for a given element
• reported on periodic table

Question 12

mass number varies from one ____ to another

Answer 12

isotope

Question 13

in a neutral atom, number of _____ = number of _____

Answer 13

protons, electrons

Question 14

electrons are not included in mass calculations

Answer 14

True, because they are much smaller

Question 15

Isotopes differ in their number of ____

Answer 15

neutrons

Question 16

How are isotopes referred to?

Answer 16

element name followed by mass number

Question 17

Only the three isotopes of hydrogen are given unique names

Answer 17

True

Question 18

protium (Greek for “first”)

Answer 18

• one proton
• 1 amu

Question 19

deuterium (Greek for “second”)

Answer 19

• one proton
• one neutron
• 2 amu

Question 20

tritium (Greek for “third”)

Answer 20

• one proton
• one two neutrons
• 3 amu

Question 21

atomic weight

Answer 21

weighted average of different isotopes per element
- leans more towards the isotope that is more apparent

Question 22

average weight implies 2 things

Answer 22

1. mass of the “average” atom of that element
2. mass of one mole of the element, in grams

Question 23

mole

Answer 23

• number of “things”
• equal to Avogadro’s number
• if atomic weight of carbon is 12 amu, implies that 6.02x10^23 of carbon atoms have a combined mass of 12.0 grams

Question 24

Avogadro’s number

Answer 24

6.02 x 10^23

Question 25

Ernest Rutherford - 1910

Answer 25

provided evidence that atom has a dense, positively charged nucleus

Question 26

Max Planck - 1899

Answer 26

developed the first quantum theory proposing that energy emitted as electromagnetic radiation from matter comes in quanta