Atomic Orbitals & The Periodic Table Flashcards
How do electrons behave within the atom?
as standing waves
What are standing waves?
waves that vibrate in time but do not move in space
What is the max no of electrons in orbitals?
2
How many quantum numbers are there?
4
What are the four quantum numbers?
- principle quantum number
- angular momentum quantum number
- magnetic quantum number
- spin magnetic quantum number
How is the principle quantum number defined?
n
What does n=1 represent?
the shell closest to the nucleus
What can be said about the greater the value of n?
the greater the value of n, the higher the energy level and further from the nucleus the electron must be
What is the second quantum number defined by?
l
What does the second quantum number determine?
the shape of the subshell
What are the range of values for l?
l has values ranging from 0 to n-1
How is the magnetic quantum number defined?
ml
What does the magnetic quantum number define?
the number of orbitals
What are the range of values for ml?
-l to l
What can be said about the shape of s orbitals?
they are spherical in shape
What happens to the size and energy of an s orbital as the value of n increases?
size and energy increase
How many possible orientations of p orbitals are there?
3
How many d orbitals are there?
5
How many orientations do f orbitals have?
7
What does the magnetic spin number do?
determines the direction of electron spin
What ways can electronic configuration be expressed?
- using quantum numbers
- orbital box notation
- spectroscopic notation
What is the Aufbau principle?
electrons fill orbitals in order of increasing energy
What is Hund’s rule?
when degenerate orbitals are available electrons fill singly keeping their electron spins parallel before spin pairing starts
What shell has more energy the 4s or 3d orbital?
3d has more energy than the 4s
What block are groups 1&2 in?
the s block
What block are groups 3& 8 in?
p block
What block are transition metals in?
d block
What is ionisation energy?
the energy required to remove 1 mole of electrons from 1 mol of atoms in the gaseous state
What happens to ionisation energy across a row?
it increases due to an increase in nuclear charge
What happens to ionisation energy down a period?
decreases down a period due to an increased shielding effect
What does VSEPR stand for?
valence shell electron pair repulsion theory
How is the number of electron pairs calculated?
e pairs=no. of outer e pairs+no. of bonded atoms/2
What is the shape of molecules due to?
the number of electron pairs or group of electron pairs
What is the relationship between lone pairs and bonded pairs?
the pairs are more repulsive than bonded pairs
What is the trend in repulsivity?
bonded to bonded< bonded to lone
Linear
2 electron pairs
180 degrees
Trigonal planar
3 electron pairs
120 degrees
Tetrahedral
4 electron pairs
109.5 degrees
Trigonal bipyramidal
5 electron pairs
90, 120, 180 degrees
Octahedral
6 electron pairs
90 degrees
Square planar
6 electron pairs
4 bonded and 2 lone
90 degrees
Pyramidal
4 electron pairs
3 bonded and 1 lone
107 degrees
What are Lewis diagrams used to demonstrate?
bonding and non-bonding electrons
