chpater 2- atomic structure and electron configuration

Isotope

Atoms of the same element with different numbers of neutrons but same numbers of protons and electrons/ electronic configuration

Relative isotopic mass

Mass of an isotope relative to the 1/12th the mass of a carbon-12 atom

Relative atomic mass

Weighted mean mass of an atom of an element relative to the 1/12th the mass of a carbon-12 atom taking into account each isotope and its abundance

What experiment could you use to determine relative atomic mass

A mass spectrometer

5 stages of mass spectrometer

1. Vaporisation

2. Ionisation

3. Acceleration

4. Deflection

5. Detection

Relative atomic mass equation

(Mass isotope A x abundance) + (mass isotope B x abundance)/ total abundance

Orbital

A regional of space in which there is high probability of finding an electrons

How many electrons can an orbital hold?

2

What is spin?

Two electrons in an orbital will repel each other and therefore possess opposite spin to counteract the repulsion between the negative charges

What do electrons initially do to prevent repulsion?

Occupy orbitals singly

Shape of S orbital

Spherical

How many electrons can an S orbital hold?

2 electrons

Shape of P orbitals

Hourglass

How many p orbitals make up the p sub shell?

3

Shape of D orbital

Like a 4 bladed propeller or an hourglass with a ring

How many D orbitals make up the D sub shell

5

Principle quantum number

Number of electrons that occupy each level 2n(2)

Convergence

The further from the nucleus, more chance of electron shells merging

Sub shell

A group of orbitals with almost the same energy level but differ in arrangement in space

Filling sub shell rules

Atomic orbitals of lower energy are filled first- atomic orbitals of the same energy fill singly before pairing starts- no atomic orbitals can hold more than two electrons

Special case of the 3d orbital

Once filled the 3d energy level falls below the 4s and the consequence is that the 4s empties before the 3d resulting in the 3d coming before the 4s in the electron configuration