After the third energy level has 8 electrons, the next electron goes into the fourth level. 4th Period: Potassium and Calcium—Electrons go into the fourth energy level. A small piece of sodium metal ...
They include lithium, sodium and potassium, and are placed in the first vertical column on the left of the periodic table. All the Group 1 elements are very reactive, and all react with water to ...
The periodic table captures a subtle pattern that runs ... is a reactive metal — just like sodium (element number 11) and potassium (number 19). A good way to think about it is to imagine ...
These are almost one-quarter of the periodic table and are mainly found in the ... sulphur, chlorine, potassium, sodium, calcium and magnesium. How polio affects the body and what WHO is doing ...