Exam 2 Flashcards
All s orbitals are spheres so..
They have no angular dependence on orientation
When does the orbital size increase?
With and increase in the value of quantum number N
All orbitals with an N>= 2 have…?
A subs hell containing 3 P orbitals
What is a node?
A plane in which the probability of finding an electron is 0 (zero electron density)
How many nodes does each orbital, s, p and d have?
1S=0 because 2s and 3s have radial nodes
P=1
D=2
For the same N value what is the relationship between P and S orbitals and PE?
With the same number N a P orbital will have higher PE because the electron density is farther from the nucleus
What is an orbital?
The electron occupies a 3 dimensional space called an orbital
What does an orbital show about the electron?
The volume of where the electron is 90% of the time
Tell me about the density of the 1s orbital
It’s greatest at its nucleus
What is the Aufbau Principal?
Electrons are placed in the lowest energy orbitals and each orbital can only obtain 2 electrons that are spin paired (opp)
What is the trend for probability density?
Highest at the Nucleus and lowest away
In general what is a shell?
Refers to an energy level
When are electrons in the same shell?
Electrons are in the same shell if they have the same N value and same type of orbital (s,p,d,f)
Each orbital has different energy
As N increases what does E do?
Increase
What type of cations do S block elements form?
Monoatomic cations by losing all their outer shell electrons leaving it with the electron configuration of the Noble Gas directly preceding it
What kind of anion does a P block element form?
A monoatomic anion by gaining enough electrons to fill its valence shell and has the configuration of the noble gas at the end of its row
What is an isoelectric ion?
Ions with the same electron configuration, (Na+,F-,Ne)
What do electrons in orbitals with the highest N values do?
They ionize first and are farther from the nucleus. So as N increases, D increases and thus E increases
What happens to the size of an atom as atomic number increases and you’re going down a group of elements?
Atom size increases
What happens to atom size with an increase in atomic number but going left to right on the table?
Size decreases
Where are the valence electrons?
In the highest energy level ( whatever # is the highest and the orbital containing it)
ANYTHING AFTER THE NOBLE GAS CONFIGURATION
Any element with an electron configuration with that of a noble gas is…?
The most abundant and thus stable
Generally what is the PE of electrons?
Basically 0 because they are infinitely far away from the nucleus
What is ionization energy?
The energy required (KJ / mil) to remove 1 mile of electrons from 1 mile of gas-phase atoms or ions in their ground state
ALWAYS REQUIRES ENERGY TO REMOVE ELECTRONS
How to find the total I.E.
It’s the sum of the ionization energies
Which orbital takes more energy to remove an electron? P or S?
S
What does the repulsion of electrons in electron configurations do?
They have higher energy and thus require less energy to be ionized
Periodic trend of I.E.?
I.E. Decreases from top to bottom of every group on the periodic table
Which orbital: Density decreases as distance increases
S orbital
If you have an anion which way on P table do you go?
⬆️
If you have a cation which way on the P table do you go?
⬇️
Why are spheres good shields?
Because they don’t have nodes
Which electrons shield the best?
Core electrons, so maximal shielding when an electron is added to a completely full shell, then shielding diminishes from there
What does adding or subtracting electrons on a regular ion do?
Dramatically change the size
As atomic radius (and thus atom size) decrease what happens to I.E.?
Increases
What is the order of screening effectiveness?
S>P>D>F
Which is better at screening- electrons in inner shells or the same shell?
Inner shells
Which elements have the highest and lowest Zeff?
He is the highest
Cs is the lowest
Which is larger- anions or a neutral atom of the same element?
Anions
Which is bigger- cations or a neutral atom of the same element?
Neutral atom of the same element
What is valence?
The capacity of the atoms of an element to form chemical bonds
What is electrostatic potetinal?
The energy a charged particle has because of its position relative to another charged particle
How is electrostatic potential related to the product of the charges of the particles and the distance between them?
Directly
Inversely
What is the constant in the electrostatic potential energy equation?
2.31X10^-19 J•nm
What energy is repulsion accompanied by?
Positive
What energy is attraction associated with?
Negative- the greater the attraction the more negative the electrostatic PE
What is lattice energy?
The stability afforded by packing ions together
Energy is released when a crystal lattice of ions is formed from the ions
What is bond length?
The distance between the nuclear centers of two atoms joined together in a bond
•have values close to the sum of the atomic radius of the atoms involved
What is bond energy? Aka bond strength
The energy needed to break 1 mole of a covalent bond in a molecule or polyatomic ion in the gas phase
What is a metallic bond?
Consists of the nuclei of metal atoms surrounded by a “sea” of shared electrons
What is electron mobility?
Metals are good conductors of electricy
What is the photoelectric effect?
States that photons must have a frequency greater than or equal to a frequency that is characteristic of a solid
What is the relationship between work function, energy, and ionization energy?
Smallest work function, smallest r energy and thus lowest ionization energy
What happens if the photon doesn’t exactly match a minimum frequency?
It won’t do anything, but in the photoelectric effect the excess energy is converted to KE
As Q1 • Q2 increases…
Potential energy becomes more negative
As D decreases what happens to PE?
It becomes more negative (stable)
When do ionic bonds generally form?
When atoms of low I.E. (Which is not difficult to lose an e-) and atoms with high negative electron affinities (which is favorable to gain an e-) get together
What are oxyanions
An anion containing one or more oxygen atoms bonded to another element
When do you add ate to the end of an oxyanion?
When it has the larger number of oxygen atoms
When do you add ite to the end of an oxyanion?
When it has less oxygen atoms
What is a binary molecular compound?
A compound that combines two nonmetallic elements
What is a binary acid?
The most simple acid, hydrogen is bonded to another nonmetallic element
What does adding an electron do to an atom?
Reduces the potential energy
What happens when you bring like charges together?
The PE sky rockets
What happens when the PE is the lowest?
It is the most stable
It’s also where bond length is measured
Does it require energy or is energy released when breaking a lattice sort?
Work and energy is used
Does energy increase or decrease when bringing ions together to make a lattice?
Decrease energy
Do covalent bonds have electrostatic force?
No because ions aren’t involved
Which type of bond is more stable, covalent or ionic?
Covalent
Why is a molecular orbital more stable?
Because the electron is near 2 nucleus
How to name ionic compounds?
List the name of the cation then prefix of the anion followed by “ide”
What do you do to name ionic compounds of transition metal cations?
CrCl2 - chromium (2) chloride so chromous chloride OUS for smaller #
CrCl3- chromium (3) chloride so chromic chloride IC is for the smaller number
What is a polar covalent bond?
A bond resulting from unequal sharing of bonding pairs of electrons between atoms-HCl
What is a dipole?
Means there is a slightly positive and a slightly negative pole on the atom (like a battery)
