Chemistry

Heisenberg Uncertainty Principle


According to Werner Heisenberg, to find the correct position of an electron, it must interact with some measuring instrument, such as radiation.

The radiation must have a wavelength in the order of uncertainty with which to determine this position.

The shorter the wavelength, the more accurate the electron is.

When you can find out where the electron is likely to be, that electron will no longer be there.

Actual model

According to Heisenberg, it is difficult to predict the correct position of an electron in its electrosphere. Schrodinger in 1926 calculated the most likely region where the electron might be. For this region gave the name of orbital.

Orbital - The region of space around the nucleus where an electron is most likely to be found.

Importantly, an isolated atom cannot be seen exactly as described in atomic models. Some techniques used by supercomputers show colored spots, showing the location of atoms of a given material. These images are obtained by a tunneling microscope, which can increase up to 28 million times.

According to the Rutherford-Bohr model, the atom has energy levels or energy layers, where each level has a maximum number of electrons. The level number represents the main quantum number (n).

Each level is divided into energy sublevels s, p, d, f. They represent the secondary or azimuthal quantum number (l).

Sublevel

s

P

d

f

QUANTIC NUMBER

0

1

2

3

MAX NUMBER OF is

2

6

10

14

The sublevel indicates the shape of the region in space where the electron is. The acronyms s, p, d, f come from English words sharp, main, diffuse and finerespectively.

Maximum number of electrons in each sublevel:

K = 1; 1s²
L = 2; 2s² 2p6
M = 3; 3s² 3p6 3d10
N = 4; 4s² 4p6 4d10 4f14
O = 5; 5s² 5p6 5d10 5f14
P = 6; 6s² 6p6 6d10
Q = 7; 7s²

The above scheme shows the notation used to indicate the number of electrons in a level and a sublevel.

Examples:
1s² - 2 é at sublevel s of level 1 (K)
2p3  - 3 é at level 2 sub-level p (L)
5d6 - 6 é at level 5 d (O)

Orbitals are identified by the magnetic quantum number (m). Indicates the orientation of this orbital in space. For each value of “l” (sublevel), m assumes integer values ​​ranging from - l…, O,… + l

Like this:

s - 1
p - 3
d - 5
f - 7

Each orbital is symbolically represented by a small square. So they can be like this:

-3

-2

-1

0

+1

+2

+3

Each orbital can contain a maximum of two electrons. But if electrons are negative charges, why don't they repel and move away?

If electrons rotate in the same or opposite direction, they create magnetic fields that repel or attract them. This rotation is called SPIN, an English word derived from the verb. to spinwhich means to rotate.