Chemistry Reference
In-Depth Information
hold 1, 6, 10, and 14 electrons respectively. We can add these numbers to-
gether to find that the fourth energy level can hold 32 e
-
(2 + 6 + 10 + 14 =
32). Another way to calculate the total number of electrons that an energy
level can hold is to use the formula 2n
2
, where n is the energy level number.
Solving for n = 4, we find that 2(4)
2
= 32 e
-
.
Try the following practice questions and check your answers.
Lesson 3 - 3 Review
1.
How many quantum numbers are used to describe each electron?
a) 1
b) 2
c) 3
d) 4
2.
Which quantum number indicates the sublevel that an electron is
found in?
a) first
b) second
c) third
d) fourth
3.
How many sublevels would the energy level represented by
n
= 4 be
broken up into?
a) 1
b) 2
c) 3
d) 4
A value for the second quantum number of 0 (
l
= 0) indicates which
type of sublevel?
a) s
4.
b) p
c) d
d) f
5.
How many orbitals does a p sublevel contain?
a) 1
b) 3
c) 5
d) 7
6.
How many total electrons can the second energy level hold?
a) 2
b) 6
c) 8
d) 16
Lesson 3 - 4 : Electron Configuration
To a chemist, the electrons in the highest energy level, which are called
valence electrons, are probably the most important part of the atom. It is
these electrons that determine the reactivity of an element. When we talk
about electron configuration, we are speaking of the arrangement of the
electrons in a particular atom
or element. By being able to
determine these arrangements,
you will be able to predict how
an element reacts with other
elements and what types of
compounds it will form. We
The Electron Configuration of Hydrogen
superscript = number of electrons in sublevel
1s
1
letter (
l
) = the sublevel
coefficient (n) = the energy level
