Chemistry - Atomic structure

What is atomic number?

Number of protons

What is mass number?

Number of protons and neutrons

What is the charge, mass and location of the 3 subatomic particles?

Electron: -1, 1/1840 and in the energy levels

Proton: +1, 1 and the nucleus

Neutron: 0, 1 and the nucleus

What is the formula for relative atomic mass?

Mean mass of an atom of an element/ 1 twelfth times mean mass of a carbon-12 isotope

What is an isotope?

An element with the same number of protons but a different number of neutrons

What is an ion?

When an atom loses or gains electrons

How many electrons in an orbital?

2

Name the 4 sub shells

s,p,d,f

What is the shape of the s and p orbitals?

spherical and dumbell

What is hunds law?

Hund's rule states that electrons occupy degenerate orbitals singly with parallel spins before pairing up, maximizing total spin and minimizing energy.

What is aufbau principle?

he Aufbau principle states that in the ground state of an atom or ion, electrons fill atomic orbitals starting from the lowest energy level to the highest.

How many electrons in an orbital?

2

How many electrons can occupy each sub shell?

s = 2

p = 6

d = 10

f = 14

List the order of sub shells from lowest to highest energy

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

Where are electrons lost from first?

Highest energy sub shells first

Name 2 elements which are the exception to the filling pattern

Chromium and copper

What rule needs to be considered when constructing the electron configuration for a transition metal ion.

Remove electrons from 4s before 3d

What is mass spectrometry used for?

To identify substances and determine the relative isotopic masses and abundances

What happens during ionisation?

Particles are converted into positive ions.

What is electron impact ionisation

High-energy electrons knock an electron off a molecule, forming a positive ion.

What is electrospray ionisation?

A sample is dissolved in a solvent and sprayed through a charged nozzle, forming positive ions.

What happens during acceleration?

Positive ions are accelerated by an electric field.

What happens during ion drift

Ions travel through a flight tube. Lighter ions generally travel faster than heavier ions.

What does the mass-to-charge ratio (m/z) mean?

The mass of an ion divided by its charge.

What does the mass spectrum show?

The relative abundance of ions against their mass-to-charge ratio (m/z).

What is the molecular ion peak?

A peak representing the molecule with an electron removed, often giving the relative molecular mass, Mr.

How can mass spectrometry identify isotopes?

1. Isotopes produce peaks at different m/z values, and their relative heights show their relative abundances.