Chemitsry unit test 2 (chemical bonding)

Question 1

What are the characteristics of a ionic chemical?

Answer 1

Crystalline solid
High melting point
Electricity conductivity as a liquid, high
High solubility in water
Electricity conductivity in water

Question 2

What are the characteristics of a molecular chemical?

Answer 2

Liquid, Gas, Solid
Low melting point
Electricity conductivity as a liquid, low
Most have low solubility in water
Does not usually conduct electricity while in water

Question 3

What is the Electronegativity scale?

Answer 3

0.0 (Pure)
0.0 - 0.4 (Non-Polar)
0.4 - 1.7 (Polar)
1.7 + (Ionic)

Question 4

Who was Dmitri Mendeleev?

Answer 4

First scientist to publish and organized periodic table
Predicted two of the undiscovered elements

Question 5

What is periodic law?

Answer 5

It states that when the elements are arranged by increasing atomic number, the elements display a regular pattern of chemical/physical properties
Elements within groups share similar traits and have the same number of valence shell electrons

Question 6

Atomic radius?

Answer 6

The size of an elements atoms
Increases in size from top to bottom per group
Smaller from left to right of each period

Question 7

Effective Nuclear Charge?

Answer 7

The pull and electron feels from the nucleus / Kind of like gravitons

Question 8

Shielding?

Answer 8

As more energy levels are added to atoms the inner layers shield the outer ones from the nucleus
Electrons move more freely closer to the outside

Question 9

Ionization energy?

Answer 9

The larger the atom the easier it’s electrons move, its similar to atomic radius
Always endothermic

Question 10

Electronegativity?

Answer 10

Measure of another atom’s attraction for another atom’s electrons
Generally,
- Metals give electrons (Low electronegativity)
- Non Metals take electrons (High electronegativity)
- Noble Gasses have little to no electro negativity

Question 11

Alkali Metals?

Answer 11

More reactive moving downwards

Question 12

Polar / Non Polar scale

Answer 12

0.0 (Pure)
0.0 - 0.4 (Non-Polar)
0.4 - 1.7 (Polar)
1.7+ (Ionic)

Question 13

What is dipole and dipole dipole?

Answer 13

The main attractive force between POLAR molecules modelled through delta and arrows.

Question 14

VESPR?

Answer 14

Valence Shell Electron Pair Repulsian

Question 15

Stability and Octet rule?

Answer 15

When atoms form bonds they gain, lose, and share electrons to create a filled shell with eight electrons
Isoelectronic
- ‘iso’ means ‘sameness’
- electronic refers to electrons
- all atoms want to be isoelectronic to the noble gasses (same electron configuration)

Question 16

What are the 3 principal types of bonding?

Answer 16

• Ionic (Metals and non-metals)
• Covalent (Non-metals and non-metals)
• Metallic (Metal and metal)

Question 17

Ionic Bonds?

Answer 17

• Metals lose all of their valence electrons
• Non-metals gain valence electrons to have a full valence shell

Question 18

Covalent bonds, terms and types?

Answer 18

• Bonding pair (The pair of electrons being shared)
• Lone pairs (Pair of electrons not being shared)
• Single bond (one line)
• Double bonds
• Triple bonds

Question 19

Metallic Bonds?

Answer 19

• Metallic elements share electrons
• Electrons can move freely within the solid metal
• Held together by the attraction between the positive nuclei and delocalized electrons

Question 20

VESPR theory?

Answer 20

• Only the valence shell electrons are important for molecular shape
• Bonded/Lone pairs of electrons are treated approximately equal
• Valence shell electron pairs repel each other electrostatically

Question 21

AXE notation?

Answer 21

A - Central atom
X - Terminal atoms
E - Lone pairs

Question 22

Polar molecules?

Answer 22

0.4 - 1.7
- Polar Bonds
- Asymmetrical
- Having polar bonds does not always mean the molecule is polar

Question 23

Dipole Moment?

Answer 23

• Show through arrow and delta symbol
• If when the dipole moments are added together they have a ‘zero’ total, the molecule is non-polar even if it has polar bonds
• this happens with symmetrical bonds
• If the dipole vectors are added and do not cancel there is a net dipole moment and the molecule is polar