4.1) Give characteristics to chemical elements with serial numbers 12, 13, 19 according to their position in D. I. Mendeleev's PSCE in accordance with the following plan:
1) Indicate the serial number of the element, the number of the period, series, group, indicate the subgroup of this element; is a metal or non-metal.
2) Indicate the charge of the nucleus of a chemical element; the number of protons, electrons, neutrons; distribution of electrons by levels.
3) Compose the electronic formula of the element.
4) Indicate the number of electrons in the external energy level, the level is completed or not completed.
5) The highest valency of the element.
6) Higher oxide and volatile hydrogen compound (if any).
7) Comparison of element activity with neighbors by period and by subgroup.
8) Which base or which acid corresponds to the highest oxide of this element.
9) Give examples of formulas of salts formed by this element, give them a name.
10) The presence of isotopes.

If you do not open the file - install the RAR archiver. Inside the archive you will find a solution in Word format.