UNIT 1) 3) Atomic Orbitals and Electron Configuration Flashcards
How can the discrete lines in atomic spectra be explained
The discrete lines observed in atomic spectra can be explained if electrons, like photons, also display the properties of both particles and waves.
Within the atom how do electrons behave
Within the atom , electrons behave as standing (stationary )waves. These are waves that vibrate in time but do not move in space
Different shapes and sizes of these “standing” waves are possible around the nucleus
What are these shapes and sizes known as ?
Different shapes and sizes of these standing waves are possible around the nucleus. These are known as orbitals
Explain what an orbital is
- it is not possible to define a space in time where an electron is found - they are constantly moving
- however the probability of finding an electron within a certain volume of space can be calculated
- : the regions where there is a high probability of finding an electron are called atomic orbitals
Therefore an orbital provides a defined volume of space where there is a high probability of finding an electron
Probability of being able to find an electron in an atomic orbital
In atomic orbitals - there is approximately 90% chance of detecting an electron
How many electrons can a single orbital hold (irrespective to size and shape)
2
Electrons within atoms are said to be _________
- what does this mean
Electrons within atoms are said to be quantised
- this means that they can only posses fixed amounts of energy known as quanta
- as a result electrons can be defined in terms of quantum numbers
What does quantum theory state
Quantum theory states that matter can only emit or absorb energy in small fixed amounts
When an electron in an atom _______ a photon of energy it moves from a lower energy level to a higher energy level. When the electron drops back down energy is _______
When an electron in an atom absorbs a photon of energy it moves from a lower energy level to a higher energy level. When the electron drops back down energy is emitted.
Rings are drawn around the nucleus of the atom to represent energy levels.
- The further away the rings are from the nucleus the ________ the energy
- as energy increases the levels become _______ together until they ________
- The further away the rings are from the nucleus the higher the energy
- as energy increases the levels become closer together until they converge
What is the convergence point
An electron that has enough energy to take it beyond the convergence point has left the atom - this means it has been ionised
Electrons are found in orbitals which are found in sub shells of energy level shells.
Each electron has an “address” how is this defined?
It is defined by a set of 4 quantum numbers
- 1st quantum number /principal quantum number
- 2nd quantum number / angular momentum quantum number
- 3rd quantum number / magnetic quantum number
- 4th quantum number / spin quantum number
1st principle quantum number
- what does this refer to
- what is the symbol
- this refers to the energy shell where the electron is located : refers to the size and energy of the shell
- symbol n
N=1 n=2 n=3 etc
What happens to the size of orbital as value n increases
As value of n increases the size of the orbital also increases
2nd quantum number - angular momentum
- what does this refer to
- symbol
- this is the type of sub shell within the energy level given letters s , p, d , f
- symbol = L
Second quantum number relating to type of sub shell
L= 0 - s sub shell 1 - p sub shell 2 - d sub shell 3 - f sub shell