Of course, other groups are also of interest. Carbon, silicon, and germanium, for example, have similar chemistries and are in Group 4 (Group IV). Carbon, in particular, is extraordinary in its ability to form many types of bonds and to be part of long chains, such as inorganic molecules. The large group of what are called transitional elements is characterized by the filling of the
subshells and crossing of energy levels. Heavier groups, such as the lanthanide series, are more complex—their shells do not fill in simple order. But the groups recognized by chemists such as Mendeleev have an explanation in the substructure of atoms.
Phet explorations: build an atom
Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!
Section summary
The state of a system is completely described by a complete set of quantum numbers. This set is written as
.
The Pauli exclusion principle says that no two electrons can have the same set of quantum numbers; that is, no two electrons can be in the same state.
This exclusion limits the number of electrons in atomic shells and subshells. Each value of
corresponds to a shell, and each value of
corresponds to a subshell.
The maximum number of electrons that can be in a subshell is
.
The maximum number of electrons that can be in a shell is
.
Conceptual questions
Identify the shell, subshell, and number of electrons for the following: (a)
. (b)
. (c)
. (d)
.
(a) If one subshell of an atom has 9 electrons in it, what is the minimum value of
? (b) What is the spectroscopic notation for this atom, if this subshell is part of the
shell?
Which of the following spectroscopic notations are allowed (that is, which violate none of the rules regarding values of quantum numbers)? (a)
(b)
(c)
(d)
(e)
(a) Using the Pauli exclusion principle and the rules relating the allowed values of the quantum numbers
, prove that the maximum number of electrons in a subshell is
.
(b) In a similar manner, prove that the maximum number of electrons in a shell is 2
n2 .
(a) The number of different values of
is
for each
and one for
Also an overall factor of 2 since each
can have
equal to either
or
.
(b) for each value of
, you get
to see that the expression in the box is
imagine taking
from the last term and adding it to first term
Now take
from penultimate term and add to the second term
.
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost
6% more than previous year? Provide with reasoning.
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Good day
How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200.
Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
I am Camara from Guinea west Africa... happy to meet you guys here
Sekou
ma management ho
Amisha
ahile becheclor ho
Amisha
hjr ktm bta ho
ani k kaam grnu hunxa tw
Amisha
belatari
Amisha
1st year ho
Amisha
nd u
Amisha
ahh
Amisha
kaha biratnagar
Amisha
ys
Amisha
kina k vo
Amisha
money as unit of account means what?
Kalombe
A unit of account is something that can be used to value goods and services and make calculations
Jim
all of you please speak in English I can't understand you're language
Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9
no Mpc is greater than 1
Y=100+.9Y+50
Y-.9Y=150
0.1Y/0.1=150/0.1
Y=1500
Kalombe
Mercy is it clear?😋
Kalombe
hi can someone help me on this question
If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output?
discuss your answer using appropriate graph.