Exam 1: Atomic Theory

Question 1

Who created the law of conservation of mass?

Answer 1

Lavoisier; 1789

Question 2

Who created the law of definite proportions?

Answer 2

Proust; 1797

Question 3

What is the law of conservation of mass?

Answer 3

Matter is neither created nor destroyed; when a chemical reaction is carried out, the total mass of the substances does not change

Question 4

What is the law of definite proportions?

Answer 4

All samples of a given compound have the same proportions of their constituent elements (regardless of their source or how they were prepared)
Ex: Water will always have 2 Hydrogens and 1 Oxygen

Question 5

What is the law of multiple proportions?

Answer 5

When two elements form two different compounds with similar bonding, the masses of element B that combine with the same amount of element A can be expressed as a ratio of small whole numbers

Question 6

Who created the atomic theory?

Answer 6

John Dalton; 1808

Question 7

What does the atomic theory say?

Answer 7

• Each element is composed of tiny, indestructible particles called atoms
• All atoms of an element have the same mass/other properties that distinguish them from atoms of other elements
• Atoms combine in simple, whole-number ratios to form compounds
• Atoms of one element can’t change into atoms of another
• In chemical reactions, atoms can change the way they are bound together w/ other atoms to form a new substance

Question 8

What makes up the nucleus?

Answer 8

protons and neutrons (held together by strong nuclear forces into dense structure)

Question 9

Who created the law of multiple proportions?

Answer 9

Dalton; 1804

Question 10

How are electrons bound to the nucleus?

Answer 10

electromagnetic forces (attraction of opposite charges)

Question 11

define atomic number

Answer 11

number of protons in an element

Question 12

define mass number

Answer 12

sum of protons and neutrons

Question 13

define atomic mass

Answer 13

average mass of an element based upon the mass of the isotopes that compose that element

Question 14

molar mass

Answer 14

g/mol

mass of given element divided by the amount of substance

Question 15

core electrons

Answer 15

innermost electrons that occupy the lowest energy levels

tightly bound to nucleus, not involved in chemical bonding, influence the chemical reactivity of the atom

Question 16

valence electrons

Answer 16

outermost electrons that occupy the highest energy levels

not held as tightly, involved in chemical bonding, influence certain properties of atoms

Question 17

aufbau principle

Answer 17

electrons are placed into orbitals of the lowest available energy

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 8s

Question 18

s orbitals

Answer 18

holds 2 electrons

Question 19

p orbital

Answer 19

holds 6 electrons (3 pairs)

Question 20

d orbitals

Answer 20

holds 10 electrons (5 pairs)

Question 21

f orbitals

Answer 21

holds 14 electrons (7 pairs)

Question 22

noble gas shortcut

Answer 22

use nearest noble gas (never above element) then only show valence electrons after

Question 23

anion

Answer 23

negative charge, gain electron

Question 24

cation

Answer 24

positive charge, lose electrons

Question 25

atomic size

Answer 25

increases as you move down a group and to the left (period)

Question 26

Ionic size

Answer 26

cations are smaller than anions

Question 27

ionization energy

Answer 27

energy required to remove an electron from an atom/ion

decreases as you move down a group and to the left

increases as you remove electrons

Question 28

electronegativity

Answer 28

ability to attract electrons

decreases as you move down the group and to the left