The element scandium is in the third family of the periodic table. Each column of the table is called a group or family, and from left to right, they are numbered one through 18. Scandium is in the third column, so it is... More »

Arsenic belongs to group 15, which is called the nitrogen family. This family of elements also includes nitrogen, phosphorus, antimony and bismuth. All elements in this family have the same electron configuration in thei... More »

Aluminum belongs to the Boron family, which is group number 13 on the periodic table of elements. The other elements in the Boron family are the metals thallium, indium, gallium and the semi-metal boron. The element alum... More »

Scandium has 21 electrons, as indicated by the element's atomic number. Scandium also has 21 protons and 24 neutrons. Its atomic symbol is Sc. More »

Hydrogen has one valence electron because it is an element found in group 1 of the periodic table. It is a simple task to find the number of valence electrons from the periodic table by looking at the group number found ... More »

Sodium is a metallic element on the periodic table with an atomic number of 11 and an atomic mass of 22.98 amu. This atomic mass is calculated by adding together the number of protons and neutrons present in the atom's n... More »

Oxygen is an element that is found in period two and group 16 on the periodic table of elements. It has an atomic number of 8 and a rounded atomic weight of 16, meaning that the element has eight protons, eight electrons... More » Science Chemistry Atoms & Molecules