Scandium atom is a rare earth metal atom, a scandium group element atom and a d-block element atom.
An element of the rare earth family of metals. It has the atomic symbol Sc, atomic number 21, and atomic weight 45.
The properties of scandium compounds are intermediate between those of aluminium and yttrium. A diagonal relationship exists between the behavior of magnesium and scandium, just as there is between beryllium and aluminium.
In the chemical compounds of the elements in group 3, the predominant oxidation state is +3.
Oxygen is the chemical element with the symbol O and atomic number 8, meaning its nucleus has 8 protons.
Oxygen is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.
Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone.
Oxygen was isolated by Michael Sendivogius before 1604, but it is commonly believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774.