For example, lithium (Li), sodium (Na ... the first practical periodic tables in the 19th century. The modern periodic table is based closely on the ideas he used. These ideas were: The elements ...

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 ...

Lithium, for example ... of these electron orbits that is reflected in the different blocks of the periodic table. Receive a weekly dose of discovery in your inbox! We'll also keep you up to ...