To learn to make electronic and graphic formulas, it is important to understand the theory of the structure of an atomic nucleus. Protons and neutrons are an atomic nucleus. Around an atomic nucleus on electronic orbitals there are electrons.
It is required to you
- - handle;
- - note paper;
- - periodic system of elements (Mendeleyev's table).
Instruction
1. Electrons in atom occupy free orbitals in the sequence called an energy scale: 1s/2s, 2p/3s, 3p/4s, 3d, 4p/5s, 4d, 5p/6s, 4d, 5d, 6p/7s, 5f, 6d, 7p. On one orbital two electrons with opposite backs – the directions of rotation can be located.
2. The structure of electron shells is expressed by means of graphic electronic formulas. For record of a formula use a matrix. In one cell one or two electrons with opposite backs can be located. Electrons are represented by arrows. The matrix demonstrates that on a s-orbital two electrons, on a p-orbital – 6, on d – 10, on f-14 can be located.
3. Consider the principle of drawing up an electronic and graphic formula on example manganese. Find manganese in Mendeleyev's table. Its serial number 25, means in atom of 25 electrons, it is an element of the fourth period.
4. Write down serial number and a symbol of an element near a matrix. According to a scale of energy captivate consistently 1s, 2s, 2p, 3s, 3p, 4s levels, having entered two electrons in a cell. 2+2+6+2+6+2=20 electrons will turn out. These levels are filled completely.
5. You had five more electrons and blank 3d - level. Arrange electrons in d-subtotal cells, beginning at the left. Electrons with identical backs arrange in cells at first on one. If all cells are filled, beginning at the left, add on the second electron with opposite to backs. At manganese five d-electrons located on one in each cell.
6. Electronic and graphic formulas demonstrate quantity of not coupled electrons which determine valency.