You will need
  • - handle;
  • paper for records;
  • - the periodic system of elements (periodic table).
The electrons in the atom occupy the available orbitals in the sequence, called the scale of energy:1s / 2s, 2p / 3s, 3p / 4s 3d 4p / 5s, 4d, 5p / 6s, 4d, 5d, 6p / 7s, 5f, 6d, 7p. On one orbital can accommodate two electrons with opposite spin rotation directions.
The structure of the electron shells Express through a graphical electronic formulas. To write formulas use the matrix. In one cell can accommodate one or two electrons with opposite spins. Electrons are represented by arrows. The matrix demonstrates that the s-orbital can accommodate two electrons, p orbitals 6, d – 10, f -14.
The matrix for records of electronic and graphic formulas
Consider the principle of making the electron-a graphic formula on the example of manganese. Find manganese in the periodic table. Its number 25 means 25 in the atom of electrons, is an element of the fourth period.
Record the serial number and the element symbol next to the matrix. In accordance with the scale of energy consistently fill in the 1s, 2s, 2p, 3s, 3p, 4s levels, typing for two electrons in a cell. Get 2+2+6+2+6+2=20 electrons. These levels are full.
Complete 1s, 2s, 2p, 3s, 3p, 4s levels of the matrix
You still have five electrons and unfilled 3d level. Place the electrons in the cells of a d-sublevel, starting from the left. Electrons with the same spin place in the cells of the first one. If all the cells are filled starting from the left, add the second electron with opposite spin. The five manganese d-electrons, are located one in each cell.
Electron-graphic formula of manganese
Electron-graphic formula clearly show the number of unpaired electrons that determine the valency.