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26 Cards in this Set
- Front
- Back
What is most electronegative atom? 2nd most? |
1. Fl- 2. O-2 |
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T or F: Period 3 (row 3) elements can have more than 8 valence electrons. |
True...don't always have to follow octet rule..can stuff electrons in d orbital |
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What is ionic bond? |
bond btw metal and non-metal e.g. CaCl2 |
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How many electrons can s,p,d,f hold? |
S holds 2 electrons P holds 6 electrons D holds 10 electrons F holds 14 electrons |
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sigma bond vs pi bond |
sigma bond = first bond atom makes with another atom pi bond = 2nd or 3rd bond atom makes with another atom |
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FYI: How do u determine the hybridization of an atom in a Lewis structure? |
First count number of pairs of free electrons and # of sigma bonds (single bonds). Do not count dbl bonds, since they do not affect hybridization of atom. Once total of these two is determined, hybridization pattern is as follows: Sigma Bonds + Electron Pairs = Hybridiz. 2 = sp 3 = sp2 4 = sp3 |
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Is this Lewis structure correct? Why or why not? |
Yes it is correct. Although Boron only has 6 in outer shell, it's unique in that does not need 8...does not follow octet rule and is fine w/6! - all formal charges are 0 - total # of VE (dots) adds up to 24 as it should |
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Which has higher energy electrons: 4s or 3d orbital? |
3d higher energy than 4s fyi- lose electrons (ie. due to ioniz) of higher energy first...these are first to react why is 4s higher energy with transition element like Sc (per khan academy)? don't need to know..lots of factors including incr nuclear charge..still can write electron config same w/ 4s orbital first e.g. 4s2 3d1 |
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How is electron config (ie. 1s2 2s2 2p6 etc) different btw Ca atom and Ca+2 ion? |
Ca+2 ion has 2 less electrons, so lose 4s2 orbital...essentially becomes same config as noble gas Argon. |
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How do your write electron config of Cr (24 e-): 1s2 2s2 2p6 3s2 3p6 4s2 3d4 or 1s2 2s2 2p6 3s2 3p6 4s1 3d5? |
1s2 2s2 2p6 3s2 3p6 4s1 3d5..very complicated FYI: Cu config also weird; 4d orbital filled before 4s = 1s2 2s2 2p6 3s2 3p6 4s1 3d10 |
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Energies and wave functions (ie. of orbitals) can be found using ? |
Energies and wavefunctions can be found using the Schrodinger Equation: Hψ = Eψ . |
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What is AufBau principle? |
electrons occupy orbital of lowest energy first |
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What is Pauli exclusion principle? |
No 2 electrons of same spin in same orbital. Every electron has unique set of quantum #s. |
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What is Hund's Rule? |
"empty bus rule" electron fill empty orbitals first..before pairing...in order to maximize multiplicity (# of unpaired electrons plus 1) and minimize coulombic πc (electrostatic repulsion) also requires that electrons be placed to give max number of parallel spins, which ↑πe (exchange energy) and lowers energy of orbitals (more stable) |
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What are the 4 quantum numbers? What does each represent?
(which is orientation? energy? shape?) |
1. principal (n = 1,2,3,etc)...determines energy of atomic orbital..basically it's the row on periodic table or distance from nucleus (if n↑, then energy↑) 2. angular momentum (L)..shape or types of orbitals present 3. magnetic (m^l)...orientation of orbital 4. spin (m^s)...+1/2 and -1/2..there are up to 2 electrons in each suborbital...1 out of 2 in + direction and other in - direction |
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How is do you calculate 2nd quantum number for Boron? |
n-1 with Boron (n=2), so max is 2-1=1 L = 0 (2s orbital), 1 (2p orbital) |
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How is do you calculate 3rd quantum number for 2p orbital? For 3s orbital? |
m^l = -L to +L for 2p there are 3 different orientations possible: -1 (2py), 0 (2pz), +1 (2px) for 3s (or any s orbital): orientation always 0..orientation of sphere always same, so only 1 possible to value |
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What is 1st and 2nd quantum # for 3d orbital? How many orientations possible? |
n = 3 L = 2 m^l = -2, -1, 0, 1, 2...so five possible orientations |
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What is concept of "shielding" referring to? |
each electron acts as shield for electrons FARTHER from nucleus, reducing attraction force of + charged nucleus (don't confuse with coulombic energy which refers to repulsion btw e's e.g. same orbital, but has nothing to do with force of nucleus) |
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Name of set of rules used to quantify the attraction force of nucleus for specific electron...by taking into account the shielding effects of electrons |
Slater's Rule - takes into account the shielding effects of electrons |
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What is formula and how do you calculate Slater's Rule? |
Z*effective nuclear charge = Z (atomic number) - S S= shielding constant...(1.0 x # of n-2 electrons) + (0.85 x n-1 e's) + (0.35 x n e's...except 1s is 0.3) nb: remember electrons cannot shield themselves, so don't include in calculation |
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VSEPR for 4 electron clouds what is bond angle in tetrahedral molecule like CH4? |
109.5 degrees |
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VSEPR for 4 electron clouds What is bond angle for NH3+? (hint: has lone paired e-'s on nitrogen) What is this shape called? |
trigonal pyramidal- lone pair takes up more space than even H-atoms...push them away making their bond angles 107° (even smaller than 109.5°) |
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VSEPR for 4 electron clouds What is bond angle for H2O? (hint: has 2 lone paired e-'s on oxygen) |
104.5 ~the more lone pairs, the more the bonds are smushed togethers |
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How do you calculate formal charge? |
VE - non bonding electrons - bonding e's / 2 |
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What are 5 d orbitals? (skip) |
see pic |