What are paramagnetic atoms
Atoms that have more electrons spinning in one direction than the other
What are diatomic atoms
Atoms with the same number of spin up and spin down electrons
What is the shielding effect
- core electrons screen valence electrons from the attractive force of the nucleus
- Balance between attractive forces (e and p) result in sheilding
What is orbital penetration
- Orbitals and sub shells define how close an electron can get to the nucleus
- The ability of an electron to get close to the nucleus is called penetration
What are periodic trends in atomic radii
- Atomic radii increases from top to bottom and right to left
- Trends in atomic size result from differences in Zeff experienced by electrons in the outermost orbitals
How atomic radii changes with the addition or loss of electron
With an addition
- Creates an anion, more e-e repulsion, larger radius
With a removal
- Creates anion, less e-e repulsion, smaller radius
What is an isoelectronic species
Two elements or ions that have the same total number of electrons
1st ionization energy trends
Ionization energy decreases from top to bottom and decreases from left to right
- As distance from nucleus to valence electron increases, the attraction lessens so its easier to pull apart
What is electron affinity
- Energy released when an electron attaches to a molecule or atom to form an ion
- The more negative the an EA value is the more likely it is to gain an electron
Trends in electron affinity
- Factors like Zeff and atomic size affect EA so trends are irregular
- Elements in group 16 and 17 have very high IE and highly negative EA, meaning they tend to lose e difficultly but attract them strongly
- Element in group 1 and 2 they have low IE and slightly negative EA meaning they lose e easily and attract them weakly
- Group 18 has very high IE and slightly positive EA and tend not to lose or gain e
Electronegativity trends
- Electronegativity decreases from the top to the bottom and from left to right
- As atomic size increases the ability for a nucleus to attract electrons decreases
Metallic characteristics
- A good heat and electricity conductor, malleability, shiny and tend to lose e in a reaction
- Metallic characteristics decrease as you move up and to the right
; increase in IE and more negative EA
What are lattice energies
- Ionic bonding is attraction between positive and negative charged ions to form lattices
- Must know the structure of ionic compound to calculate lattice energy
Trends in lattice energies
- Ions with a greater charge create higher energy lattices
- Smaller ions can get closer together, increasing the interaction between them (thus the lattice energy)
What are bond strengths
- Its a measure of how much energy is required to break a bond
- Bond length decreases as bond strength increases
Whats a non-polar covalent bond
- Bonding electrons shared equally
- No charges on atoms
Whats a polar covalent bond
- Bonding electrons shared unequally
- Partial charges on atoms
Whats an ionic bond
- Complete transfer of one or more valence electrons
- full charges on resulting ions
What is Ionization Energy?
The minimum energy required to remove an electron
2nd ionization energy
Second ionization energy: The energy it takes to remove an electron from a 1+ ion (meaning the atom has already lost one electron and now removing the second).
1st ionization energy
first ionization energy of an element is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase.
