Chemitsry unit test 2 (chemical bonding) Flashcards
What are the characteristics of a ionic chemical?
Crystalline solid
High melting point
Electricity conductivity as a liquid, high
High solubility in water
Electricity conductivity in water
What are the characteristics of a molecular chemical?
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
What is the Electronegativity scale?
0.0 (Pure)
0.0 - 0.4 (Non-Polar)
0.4 - 1.7 (Polar)
1.7 + (Ionic)
Who was Dmitri Mendeleev?
First scientist to publish and organized periodic table
Predicted two of the undiscovered elements
What is periodic law?
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
Atomic radius?
The size of an elements atoms
Increases in size from top to bottom per group
Smaller from left to right of each period
Effective Nuclear Charge?
The pull and electron feels from the nucleus / Kind of like gravitons
Shielding?
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
Ionization energy?
The larger the atom the easier it’s electrons move, its similar to atomic radius
Always endothermic
Electronegativity?
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
Alkali Metals?
More reactive moving downwards
Polar / Non Polar scale
0.0 (Pure)
0.0 - 0.4 (Non-Polar)
0.4 - 1.7 (Polar)
1.7+ (Ionic)
What is dipole and dipole dipole?
The main attractive force between POLAR molecules modelled through delta and arrows.
VESPR?
Valence Shell Electron Pair Repulsian
Stability and Octet rule?
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)
What are the 3 principal types of bonding?
- Ionic (Metals and non-metals)
- Covalent (Non-metals and non-metals)
- Metallic (Metal and metal)
Ionic Bonds?
- Metals lose all of their valence electrons
- Non-metals gain valence electrons to have a full valence shell
Covalent bonds, terms and types?
- Bonding pair (The pair of electrons being shared)
- Lone pairs (Pair of electrons not being shared)
- Single bond (one line)
- Double bonds
- Triple bonds
Metallic Bonds?
- Metallic elements share electrons
- Electrons can move freely within the solid metal
- Held together by the attraction between the positive nuclei and delocalized electrons
VESPR theory?
- 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
AXE notation?
A - Central atom
X - Terminal atoms
E - Lone pairs
Polar molecules?
0.4 - 1.7
- Polar Bonds
- Asymmetrical
- Having polar bonds does not always mean the molecule is polar
Dipole Moment?
- 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
