Principles and application
groups n valence elect
periodic trends
additional
additional
100
What is Aufbau's principle?
Electron's occupy the lowest energy levels first.
100
group 1 is what metals and how many valence electrons do they have?
group 2 is what metals and how many valence electrons do they have?
group 3-12 is what metals and how many valence electrons do they have?
Group= number of valence electrons
Group 1- Alkaline metals w/ 1 valence electron
Group 2- Alkaline earth metals w/2 valence electrons
Group 3-12- Transition metals w/ varying valence electrons
100
What is nuclear charge?
The total positive energy of the nucleus. The more protons in the nucleus, the stronger the pull on the electrons.
Nuclear charge increases across a period (from left to right) because protons increase.
Ex. Li to Be
100
What is one exception in ionization energy?
Hint: N
From O to N, the ionization energy increases because Nitrogen has a half-filled 2p shell. Oxygen has one more electron than N, which is paired with another electron in it's 2p subshell, leading to electron-electron repulsion, making it slightly easier to remove.
100
Who is MENDELEEV and what did he do?
Who is MOSLEY and what did he do?
HOW DO YOU FIND MASS NUMBER?
Mendeleev created the first periodic table and arranged it by atomic mass.
MOSLEY rearranged Mendeleev's periodic table and arranged it by ATOMIC NUMBER. The modern periodic table is organized by atomic number.
MASS NUMBER = PROTONS PLUS NEUTRONS.
200
Aufbau's principle- What's the order for filling sublevels? lowest to highest
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p
200
group 13 is what metals and how many valence electrons do they have?
group 14 is what metals and how many valence electrons do they have?
group 15 is what metals and how many valence electrons do they have?
group 13- boron group w/ 3 valence electrons
group 14- carbon group w/ 4 valence electrons
group 15- nitrogen group w/5 valence electrons
200
What is atomic size/radius?
Atomic size is how big an atom is. Atomic radius increases down a group (from top to bottom) - similar to shielding affect
Because there is an increase in shielding affect, the additional electrons shells makes atoms larger since electrons are further from the nucleus.
Atomic radius decreases across a period because protons increase, and the nuclear charge brings the electrons closer.
200
how many sig figs in each of these numbers?
945.30 450.0 25.0 307
0.00064
25.3
0.00456
945.30: 5 450.0: 4 25.0: 3 307: 3
0.00064: 2
25.3: 3
0.00456: 3
200
HOW DO YOU FIND AVERAGE ATOMIC MASS?
HOW DO YOU FIND PERCENT ABUNDANCE?
AVG ATOMIC MASS/AAM= (mass # x percent)+ (mass # x percent ) / 100
PERCENT ABUNDANCE: ex. mass numbers 63 and 65
AAM= 63 (100-y) + 65y
Refer to notes.
300
What's Pauli's exclusion principle?
When two electrons occupy the same orbital, they must have opposite spin
Ex. In an orbital diagram, one arrow has to point upwards, the other points downwards.
300
group 16 is what metals and how many valence electrons do they have?
group 17 is what metals and how many valence electrons do they have?
group 18 is what metals and how many valence electrons do they have?
Group 16- Oxygen group w/ 6 valence electrons
Group 17- Halogens w/ 7 valence electrons
Group 18- Noble gas w/8 valence electrons
300
What is ionization energy?
Ionization energy is energy needed to remove the first electron from an atom.
Ionization energy decreases down a group because shielding effect increases and electrons are farther away from the nucleus which is easier to remove.
Ionization energy increases across a period because nuclear charge increases, there are more protons so there is more attraction to the electrons making them harder to remove.
300
What is accuracy and what type of error affects accuracy? How do we calculate accuracy?
What is precision and what types of errors affects precision? How do we calculate precision?
Accuracy - The closeness of a measurement to it's true value. Affected by systematic error (a consistent error) Systematic error= Percent error= "measured value - true value/ true value x 100"
Precision- The closeness of measured values to each other. Affected by random error. Random error= percent uncertainty. "Absolute uncertainty/ value x 100"
300
What is the quantum mechanical model and how do electrons move through the atom?
QUANTUM MECHANICAL MODEL (BOHR MODEL)
Electrons move through the atom by going from orbital to orbital.
400
What is Hund's rule?
Every orbital in a sub-level is filled halfway or with one electron before any orbital is filled with two electrons. All single electrons in orbitals of equal energy (p's, d's and f's have the same spin.) - one arrow going upward on each before you do downward arrow
400
What are the two exceptions in configurations?
Chromium, Cr= 1s2 2s2 2p6 3s2 3p6 4s1 3d5
Copper, Cu= 1s2 2s2 2p6 3s2 3p6 4s1 3d10
400
What is electronegativity?
Electronegativity is the ability of an atom to attract electrons to itself when it is bonded to another atom.E
Electronegativity decreases down a group due to increase shielding effect. Inner electrons shield outer electrons making it harder to attract electrons.
E-neg increases across a period because increased nuclear charge allows for the protons to attract more electrons.
400
What is a physical change? Give examples
What is a chemical change? Give examples.
A physical change is a change in appearance or physical state. Ex. Melting, boiling, evaporating, shredding paper, cutting wood.
A chemical change is a change in chemical composition. Ex. Oxidating, rusting, tarnishing.
400
What is the light produced when x falls to x level.
When an atom falls to n=2, it produces visible light.
When an atoms falls to n=1, it produced ultraviolet light.
When it falls to THIRD level or HIGHER, INFRARED radiation is produced.
500
What is the number of orbitals for each and the max number of electrons?
S
P
D
F
S - 1 orbital, max 2 electrons 2s2
P - 3 orbitals,7 max 6 electrons 2p6
D- 5 orbitals, max 10 electrons 3d10
F- Max 7 orbitals and 14 electrons 4f14
500
What is shielding effect?
Shielding effect is when the inner electrons block the attraction of the nucleus from the outer (valence) electrons.
Thus, giving the outer electrons more freedom since they are held less tightly.
Shielding effect increases down a group/column. Ex. Li to Cs.
500
What is one exception in ionization energy?
Hint: B
B's ionization energy is slightly lower than Be even though ionization energy increases across a period.
This is because B has an electron in the 2p orbital which is easier to remove due to less nuclear charge from increase shielding effect.
500
Define these separation techniques
Filtration
Evaporation
Distillation
Filtration- Separation based on size, larger ones are trapped on the filter and smaller ones pass through.
Evaporation: Separates solids and liquids by adding heat to vaporize the liquid and leave the solid behind.
Distillation: Separation based on boiling points. Ex. A mixture of alcohol and water, alcohol has a lower boiling point so it will evaporate first and leave water behind.
500
list the electromagnetic spectrum from low to high energy
1. radio waves
2. microwaves
3. infrared
4. visible light
5. Ultraviolet
6. X-rays
7. Gamma rays.