Modern periodic table In the modern periodic table, each period starts with the strong metal (in group 1 (1 A), where the metallic property decreases by increasing the atomic number, till we reach the...
The awareness of protecting natural life increased after great harmful consequences that appeared since the mid-twentieth century. As each species of the plant gets extinct, 30 species of animals that rely on it as...
Non-metals The non-metals are the elements that have more than four electrons in their outermost energy levels, The non-metals are characterized by the smallest atomic sizes and the largest electronegativity.
The metals Metals are the elements that have less than four electrons in their outermost energy levels, During the chemical reactions, the atoms of the metallic elements tend to lose their outermost electrons, and...
