Unit 6: Electrons in Atoms Flashcards
JJ Thomson’s model?
Plum pudding model
What does Rutherford Model show?
most of the mass in nucleus and e- in empty space
Bohr Model
e- in concentric orbit around nucleus and e- exists in energy levels
What are the energy levels like closest to the nucleus?
low energy levels
What are the energy levels like farthest from the nucleus?
high energy levels
Electron Configuration
Lists the SUBLEVELS (or energy levels) filling with electrons in order of increasing energy
What does the first number represent in a sublevel
energy level (the row)
What does the letter represent in a sublevel
type of orbital
What does the superscript represent in a sublevel
number of electrons
Periods on the periodic table are…
rows
What are the types of atomic orbitals?
s, p, d, f
Energy Levels
regions around the nucleus where electrons are likely to be moving
Where is the s orbital on the periodic table?
first 2 columns (and Helium)
Where is the p orbital on the periodic table?
last 6 columns
Where is the d orbital on the periodic table?
in the middle of
What energy level does the d orbital begin with on the periodic table?
3
How many electrons in the s orbital?
2
How many electrons in the p orbital?
6
How many electrons in the d orbital?
10
How many electrons in the f orbital?
14
What energy level does the f orbital start from?
4
Standard Notation of Electron Configuration
ex. 1s2 2s2 2p6
Shorthand Configuration
standard Notation that starts with the nearest noble gas before the desired element
ex. [Ar] 4s2
Orbital Diagrams: Box Configuration rules
each box contains 2 electrons
electrons are arrows
arrows are paired in opposite directions
each orbital must be labeled
ex.) 3 boxes for p orbital, 5 boxes for d orbital
How many electrons can each energy level hold? (Starting from 1)
2, 8, 18, 32
What orbitals are in energy level 1?
s
What orbitals are in energy level 2?
s, p
What orbitals are in energy level 3?
s, p, d
What orbitals are in energy level 4?
s, p, d, f
Aufbau Principle
fill up the lowest energy levels and orbitals first
Pauli’s Exclusion Principle
Electrons MUST have opposite spins in orbitals
(arrows pointing in opposite directions)
Hund’s Rule
place one electron in each orbital (with the same spin) and then pair them up
Valence Electrons
Electrons on the outermost shell
(the highest energy level)
Positive ion
Cation
Cation
Positive Ion
Negative Ion
Anion
Anion
Negative Ion
______ lose valence electrons
metals
How do you identify the valence electrons and cation symbol?
The highest energy level with electrons indicate the valence electrons
Number of valence electrons = amount of positiveccharge
ex) 3s2 - 2 val = Mg2+
______ gain electrons
non-metals
Octet
A full outer shell of electrons (8)
How to identify anions and their valence electrons
Valence electrons is the highest energy level’s (number) electrons
how many electrons needed to complete an octet = the negative charge
ex) 3s2 3p5 - 7 val - Cl- (because one less than 8)
