Actinium

                             

• Actinium is a radioactive chemical element with atomic number is 89 and it symbol Ac.
• The chemical behaviour of actinium is similar to that of the rare earths, particularly lanthanum.
• Although actinium is present in the earth's crust and it is found in only trace amounts. It is one of the ten rarest elements.
• Actinium glows in the dark as it is so highly radioactive. The glow emitted by actinium is bluish in color.