Atom Flashcards
An energy Level
A fixed amount of energy an electron can have in an atom
The excited state
State where an electron occupies an orbital in a higher energy level than those available at the ground state
The Ground State
State where an electron occupies the lowest energy level
An atomic orbital
A region of space where there is high probability of finding electrons
A sublevel
A subdivision of main energy level that consists of one or two more orbitals of same energy level
Heisenbergs Uncertainty Principle
You cant predict at the same time the velocity and position of an electron in an atom
Principles of atomic absorption theory
1) Atoms of the same element in the ground state absorb light of a particular wavelength that is charachteristic to that element
2) The amount of light absorbed is directly proportional to the concentration of an element in a sample
Use Bohr Atomic Theory to Explain lines on emission spectrum of hydrogen
1) Atoms in ground state are restricted to fixed amount of energy and occupy lowest avaliable energy level
2) When an atom absorbs energy it jumps to a higher energy level
3)Atoms in excited state are unstable and can drop to lower energy level with release of energy from atom in form of photon or light
4) The difference in energy between E2-E1 =Hf determines definitie colour or wavelength of photon that appears as colour or wavelength on line emission spectrum
Appearance of line emission spectrum
Coloured lines on dark background
Why does each element have unique line emission spectrum
Each element has unique electron configuration which gives rise to unique electron transition
Limitations to Bohrs Theory
1) Only works for hydrogen
2)Doesnt take heisenberg uncertainty principle into account
Differences between orbit proposed by bohr and orbital
1) Orbit is 2d shape while orbital is 3d shape
)Orbit says theres definetly electron while orbital says theres high probability of electron
Differences of Bohrs Theory and Modern Atomic Theory
1) Bohrs theory does not account for wave nature, Modern theory accounts for wave nature so only probability of finding electron can be calculated
2) Heisneberg uncertainity principle
Why is it hard to find covalent radius of atom
Cant predict, at same, time, velocity and position of atom
Line emission spectrum
Series of lines in infared region
Balmers Series
Drops to n=2
Two pieces of evidence for existence of sublevels
1) Only fixed energy emitted from atom
2)Atomic absorption theory shows energy levels have sublevels close together in energy
Why is there no orange line in hydrogen emission spectrum
E2-E1 =HF for yellow photon
3) No corresponding electron transition
Difference between 2s and 2p sublevels
2s, Holds max of 2 electrons, fills up with electrons before 2p sublevel
2p: Holds max 6 electrons
after 2s
Difference between p orbital and p sublevel
Orbital( holds max 6 electrons) and is one p orbital
Sublevel: Holds max 6 electrons and is 3 p-orbitals
Difference between s and p orbital
S orbital is spherical shaped
P orbital is dumbell shaped
