Physical - Atomic Structure Flashcards
What is relative atomic mass?
The average mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12.
What is relative isotopic mass?
The mass of a single isotope of an element relative to 1/12th of the mass of an atom of carbon-12.
What is mass spectrometry?
An analytical technique that measures the mass to charge ratio of different ions.
What do electrons occupy?
energy levels
How are energy levels referred to?
Energy levels are referred to by their principal quantum number, n. The higher the principal quantum number/energy level, the more energy the electrons in it will have.
What are sub-levels?
Each energy level contains one or more sub-levels/sub-shells. These sub-levels have the names s, p, d and f.
How many electrons can the s sub-level hold?
2
How many electrons can the p sub-level hold?
6
How many electrons can the d sub-level hold?
10
How many electrons can the f sub-level hold?
14
What does isoelectronic mean?
When species (atoms/ions) have the same electron configuration.
What are orbitals?
An atomic orbital is a region around the nucleus that can hold up to 2 electrons with opposite spins. Each sub-shell is made up of orbitals.
Different atomic orbitals have different energies. Each orbital has a number that tells us the main energy level that it corresponds to. The atomic orbitals of each main level have different shapes, which in turn have slightly different energies. These are the sub-levels.
How many orbitals does the s sub-level have?
1 (2 electrons in total)
How many orbitals does the p sub-level have?
3 (6 electrons in total)
How many orbitals does the d sub-level have?
5 (10 electrons in total)
How many orbitals does the f sub-level have?
7 (14 electrons in total)
How are electrons shown in orbitals?
Electrons are shown in orbitals using arrows in box notation. Electrons in the same orbital have opposite spins.
What are the rules for determining electron configuration?
- Aufbau (construction) Principle
- Hund’s Rule
- Pauli Exclusion Principle
- Ion Formation
What is Aufbau’s (construction) Principle?
Electrons fill the lowest energy orbital available first.
What is Hund’s Rule?
If we have orbitals with the same energy, then we put electrons into individual orbitals before we pair them up. This is because electrons in the same orbital repel.
What is Pauli’s Exclusion Principle?
We can have up to 2 electrons in the same orbital but they must have opposite spins.
What is the Ion Formation rule?
Atoms lose electrons from the highest occupied orbital but transition metals lose 4s before 3d.
Which elements are the exception to the rules?
Chromium and Copper.
What is an electron?
A cloud of negative charge. The negative cloud charge has the shape of the orbital occupied by the electron.