Unit 3 - Atoms And Molecules

Question 1

What was John Dalton atomic Theory?

Answer 1

• all elements are composed of atoms
• atoms of same element are alike while atoms of different elements are different
• atoms are indivisible
• atoms of elements combine in the ratios of whole #s to form compounds

Question 2

What subatomic particle did J.J. Thomson discover?

Answer 2

The electron

Question 3

What did Robert Millikan do?

Answer 3

He determined the charge on an electron

Question 4

What did Ernest Rutherford discover?

Answer 4

The proton

+ 3 types of radioactive emissions

Question 5

What did Neils Bohr use to describe the organization of electrons with an atom?

Answer 5

Quantum Theory, which talked about orbits and energy levels

Question 6

What did Louis de Beoglie propose?

Answer 6

Wave Model of atom

Question 7

What did Edwin Schrodinger and Werner Heisenberg contribute?

Answer 7

• Electron Cloud Model

* developed quantum #s

Question 8

What did James Chadwick discover?

Answer 8

Neutrons

Question 9

How do you find the mass number?

Atomic number/Number of protons?

Number of neutrons?

Answer 9

1. Round atomic mass to nearest while number
2. Top left number on element
3. Mass # - Atomic # = # of neutrons

Question 10

What are isotopes?

Answer 10

Atoms with the same # of protons but different # of neutrons

Question 11

What is the Pauli Exclusion Principle?

Answer 11

No two “e” in the same atom can be described by the same 4 quantum numbers

Question 12

What is the Aufbau Principle?

Answer 12

Fill lowest energy orbitals first when filling orbitals

Question 13

What is Hund’s Rule?

Answer 13

The most stable configuration is the one with max # of unpaired electrons with the same spin

Question 14

What are the 4 quantum numbers?

Answer 14

n = shell; describes energy level

L = subshell; describes shape and type of orbital

mL = orbital; describes the # of electrons in each subshell and their orientation

ms = magnetic spin

Question 15

What are Intermolecular Forces and the 4 types of those forces?

Answer 15

They are the attractive forces between molecules and between ions and molecules

1. Dipole - Dipole
2. Hydrogen bonds
3. London Dispension Forces
4. ion - Dipole forces

Question 16

What is Polar Covalent?

Answer 16

It’s when electrons are shared unequally between 2 atoms (due to differences in electro Negativity)

Question 17

What is Hydrogen Bonding?

Answer 17

• a stronger version of a Dipole-Dipole force

* found in molecules containing HYDROGEN and FON (Fluoride, Oxygen, or Nitrogen)

Question 18

What are Ion-Dipole Forces?

Answer 18

• Attraction force between an ion and a neutral molecule that has a dipole
• most commonly found in solutions

Question 19

What are London Forces?

Answer 19

Weak force that holds non-polar molecules together when in liquid and solid states

Question 20

What are Dipole-Dipole Forces?

Answer 20

• Forces of attraction between positively charged ends of polar molecules

Question 21

What did Mendeleev create?

Answer 21

The original Russian-version Periodic Table, where trends could be seen when the elements were ordered by atomic weight

Question 22

What is the Trend of Atomic Radius?

Answer 22

DECREASES from L > R across a period

INCREASES from T > B in a group/family
Due to shielding effects and larger orbitals

Question 23

What is Electronegativity and its trend?

Answer 23

• the attraction an atom has for a shared pair of electrons in a covalent bond

INCREASES from L > R across a period

DECREASES from T > B in a group/family

Question 24

What is Ionization Energy and its trend?

Answer 24

• energy needed to remove an electron

INCREASES from L > R across a period

DECREASES from T > B in a group/family

Question 25

What is Electron Affinity and its trend?

Answer 25

• energy associated with the addition of an electron to an atom

INCREASES from L > R across a period

DECREASES from T > B in a family/group