Models of the atom
What did Erwin Schrödinger discover?
the electron is a circular standing wave around the nucleus (equation used to calculate electron energy levels)
What does "Quantized energy" mean?
electrons can possess only certain discrete energy values
Which element's valence electron has the following quantum numbers: [2,1,0, +1/2]
Carbon
Provide an example of a linear molecule
CO2
Describe the relationship between electronegativity and bond polarity
electronegativity is how strongly an atom attracts a pair of electrons it shares with another atom...the difference in electronegativity between atoms states how "polar" the molecule is (whether electrons are shared equally or not)
Based on Thompsons model of the atom, what did Rutherford expect to see during his experiment?
alpha particles should have moved straight through, but were instead deflected
if the value of L (2nd quantum number) is 3, what letter is used?
f
Which element has a 4d^2 configuration for its last electron?
Zr
What is the shape of hydrogen cynanide (HCN)
linear
Which is the most electronegative element: helium, hydrogen, sodium, fluorine, francium?
fluorine
What was the problem with Rutherford's model of the atom?
An electron that was constantly accelerating would lose energy and should therefore not maintain its orbit around the nucleus, but rather spiral into the centre and collide with the nucleus
What does the magnetic quantum number (ml) refer to?
Determines how many orbitals there are of a type per energy level...describes a specific orbital amongst a particular set
What is the electron configuration for a halogen?
1s^2 2s^2 2p^5
What is the molecular shape for a sulfate ion (SO4^-2)?
tetrahedral
is H2Te polar or nonpolar?
polar
What was the issue with the bohr model?
It did not account for multi-electronic atoms
What is the pauli exclusion principle?
In a given atom, no two electrons can have the same set of four quantum numbers
Draw an energy diagram for the valence shell of oxygen
two arrows in 2s, 2 in first 2p, one arrow each in 2nd and third 2p
How does VSEPR play a role in molecule polarity?
Symmetry/ geometric shape of molecule (net dipoles)
Which is more polar, H2O or CO2? Explain how you know
H2O has a bent shape, making it asymmetrical and more polar than CO2 (which is linear, therefore symmetrical and non-polar)
What is the Heisenberg uncertainty principle?
It is impossible to know the exact position and speed of an electron.
The two main ideas of the quantum mechanical model of the atom are:
Write the long and short electron configuration for chlorine
[Ne] 3s² 3p⁵
Is tetrafluoromethane polar or non-polar? How do you know?
atoms bonded are identical to each-other and evenly spaces apart, therefore the dipoles cancel out (symmetrical), non-polar
Name a molecule that follows this criteria: trigonal planar, non-polar
eg. BF3