Compare the chemical elements lithium, beryllium and boron.
November 14, 2020 | Education
| PLAN | lithium | beryllium | boron |
serial number; | 3 | 4 | five |
position in the Periodic Table (period number, group number, subgroup); | 2 period, I group, main subgroup |
2 period, II group, main subgroup |
2 period, III group, main subgroup |
the number of protons in the nucleus of an atom; | 3 | 4 | five |
number of energy levels | 2 | 2 | 2 |
total number of electrons; | 3 | 4 | five |
the number of electrons at the external energy level | 1 | 2 | 3 |
