Unit 1 Inorganic Chemistry: Key Area 2 - Atomic orbitals, electronic configurations and the periodic table 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.
How do electrons behave in an atom?
Electrons behave as standing (stationary) waves in an atom. These are waves that vibrate in time but do not move in space. There are different sizes and shapes of standing wave possible around the nucleus, known as orbitals. Orbitals can hold a maximum of two electrons.
What are orbitals defined as?
An area where there is a 90% probability of finding an electron.
What are the 4 quantum numbers?
- Principle Quantum Number (n)
- Angular Momentum Quantum Number (l)
- Magnetic Quantum number (m)
- Spin Magnetic Quantum Number (s)
What is the meaning of the Principal Quantum Number?
Energy Level
What is the meaning of the Angular Momentum Quantum Number?
Shape of the Orbital
What is the meaning of the Quantum Number?
Orientation
What is the meaning of the Quantum Number?
Electron Spin
What is the fixed amount of energy of electrons within atoms called?
Quanta
What does the Principal Quantum Number tell you about an atom?
The average relative distance of the elctron from the nucleus. Is measured in n = 1,2,3,4…
What does a higher value of n in the Principal Quantum number indicate?
The higher the value of n, the higher the potential energy associated with the shell and electrons are easier to remove from an atom.
What does the angular momentum quantum number describe?
The shape of the orbital.
What are the possible values of l in the angular momentum number but what is used instead?
Any integer value from 0 to n-1. L = 0,1,2 and 3 but letters s,p,d and f are used instead.
If the value of n is 1, what is the value of l and the subsequent sub-shell?
l = 0 and 1s
If the value of n is 2, what is the value of l and the subsequent sub-shell?
l = 0/1 and 2s/2p
If the value of n is 3, what is the value of l and the subsequent sub-shell?
l = 0/1, 2 and 3s/3p, 3d
If the value of n is 4, what is the value of l and the subsequent sub-shell?
l = 0/1, 2/3 and 4s/4p, 4d/4f
How many atomic orbitals are there within a s sub shell?
1
How many atomic orbitals are there within a p sub shell?
3
What are the key features of the s orbital?
- Spherical
- The s orbital in the first shell is smaller than the s orbital in the second shell.
What are the key features of the p orbital?
- Each p orbital has two lobes.
- Three p orbitals are DEGENERATE (have the same energy as each other).
- They are aligned along perpendicular axes.
What are different about d orbitals?
The five d orbitals are DEGENERATE with each other but have higher energies than the s and p orbitals in the same shell.
What MUST be known about orbitals?
- The shapes of s and p orbitals and be able to draw them. • Max number of 2 electrons in any orbital
- Recognise d orbitals from diagrams
- Know that d 2 has a different shape