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2.17 g Na/ (22.9898 g/ mol Na) = 0.09439 mol Na * (6.022*10^23)
= 5.68 * 10^22 atoms
80 (molar mass)
35 (atomic #/ # of protons)
80 - 35 = 45 (# of neutrons)
Gallium : Group 13 : Ga 3+ (2)
Oxygen : Group 16 : O 2- (3)
Its all about balance kiddos
Sc 3+: 21e -3e = 18e
Mn5+: 25e -5e = 20e
K+: 19e-1e= 18e
one of these things is not like the other
The MAX any orbital can hold is 2!!!!
lets be real this tripped me up for approximately ten minutes solely because i am apparently illiterate... the key word here is VALENCE as in only the outer shell
so only level 4 energy levels should be included
the element this question alludes to is Ge [ Period 4, Group 4a]
and this element has a full 4s2 orbital and only 2 electrons in the p orbitals
s: spherical shape
p: peanut shape
d: double peanut shape
The Bohr model only works for elements and ions with 1 electron
Extra Cool Stuff:
This model depicts an atom as a solar system of sorts even though planets don't circularly revolve around the sun, they go in a more elliptical fashion [ attraction is provided by electrostatic forces rather than gravity]
Basically despite its extreme restrictions its still notable because of its success in explaining the Rydberg formula for the spectral emission lines of atomic hydrogen
According to the Aufbau principle electrons orbiting one or more atoms fill the lowest available energy levels before filling higher levels so 4s is filled before 3d, and one would assume when removed that 3d electron would be removed first but as per usual nothing is as it seems in chemistry apparently so the exact opposite occurs! And its not just because God is unjust and Butherus is coming after you personally but because as 3d fills up it's energy levels decrease so 4s is removed first as it has the highest energy
2d does not exist as a state or configuration
2 electrons are removed from the 4s level leaving the 3d level the same with 7 electrons and 3 unpaired electrons
Remember the Mn5+ structure you probably drew or thought up earlier. it only has one unpaired electron, therefore it is paramagnetic
Which of these diagrams could represent the ground state of the d valence electrons of V?
Due to the Hund's Rule and Pauli Exclusion principle it can't be A or C.
Basically electrons need to be spinning the same way, until they get partners that will spin the other way. And that electrons can't be paired until every sub orbital is filled.
And because V only has three electrons in the d level we are left with B.
Use the Rydberg formula:
0.7225(30) + (1-0.7225)(32) = 30.55
n=3 --> principle quantum number (n) --> describes the size of the orbital [indirectly describes the energy of an orbital]
l= 0,1,2 --> can be any integer between 0 and (n-1)
ml: 0, -1<m<1, -2<m<2 --> any integer between -1 and l
ms: +1/2 or -1/2
It can't be A (ml) or C (l) or D (ms).
11 protons/ atomic # = Na (sodium)