Chemistry- The Periodic Table (Year 8)


The Periodic Table:

All the different elements, are arranged into the periodic table. 

The elements are arranged in order of increasing atomic number. The vertical columns are called groups, and the horizontal rows are called periods. 

In period one, the atoms have one shell of electrons, in period two, the atoms have two shells of electrons, in period three the atoms have three shells of electrons, and so on. The periods show the same number of shells of electrons. (e.g. period one has one shell of electrons, period two has two shells of electrons, and period three has three shells of electrons). The groups show the same number of electrons in their electron shell. 

Group 1 chemicals are very reactive, elements in group 1 become more reactive as you go down the group. Ths is because, in a group 1 atom, the negative electron, in the outer shell is trying to leave, but the atoms nucleus is positively


No comments have yet been made