Atomic orbitals, electronic configurations and the periodic table !!

Electrons behave as?

Standing waves in an atom

What are standing waves?

These are waves that vibrate in time, but do not move in space

There are ____________ of standing waves possible around the nucleus, known as ….?

• different sizes and shapes

• Orbitals

What is the maximum number of electrons that an orbital can hold?

2 electrons

The different shapes of orbitals are identified as?

S Orbital

P Orbital

D Orbital

F Orbital

What is quanta?

Fixed amounts of energy in electrons within atoms

What are the four quantum numbers?

• The principal quantum number

• The angular momentum quantum number

• The magnetic quantum number

• The spin quantum number

What does the principal quantum number indicate?

The main energy level for an electron and is related to the size of the orbital

What does the angular momentum quantum number determine?

The shape of the subshell and can have values from 0 to n - 1

What does the magnetic quantum number determine?

The orientation of the orbital and can have values between -L and +L

What does the spin magnetic number determine?

The direction of spin and can have values of +1/2 or -1/2

Electrons within atoms are arranged according to:

• The aufbau principle

• Hunds rule

• The Pauli exclusion principle

What is the aufbau principle?

Electrons fill orbitals in order of increasing energy

What is the Hunds Rule?

When degenerate orbitals are available, electrons fill each singly, keeping their spins parallel before spin pairing starts

What is the Pauli exclusion principle?

No two electrons in one atom can have the same set of four quarter term numbers therefore no overtorquing more than two electrons and these two electrons must have opposite spins

In an isolated atom, the orbitals with each subshell are?

Degenerate

The more stable the electron configuration, the what?

Higher the ionisation energy

The number of electron pairs surrounding essential atom can be found by:

• Taking the total number of valence electrons on the central atom and adding one for each atom attached

• Adding an electron for every negative charge

• Removing an electron for every positive charge

• Dividing the total number of electrons by 2 to give the number of electron pairs

Electron pairs are what?

Negatively charged and repel each other

How are electron pairs arranged?

They are arranged to minimise repulsion and maximise separation

The arrangement of electron pairs around a central atom is?

• Linear for two electron pairs

• Trigonal planar for three electron pairs

• Tetrahedral for four electron pairs

• Trigonal bipyramidal for five electron pairs

• Octahedral for six electron pairs

Shapes of molecules or polyatomic ions are determined by what?

The shapes adopted by the atoms present based on the arrangement of electron pairs

Electron pear repulsion is decrease in strength in the order?

Non-bonding pair/non-bonding pair > non-bonding pair/bonding pair > bonding pair/bonding pair