Scientists use the periodic table to quickly refer to information about an element, like atomic mass and chemical symbol. The periodic table’s arrangement also allows scientists to discern trends in ...

Atomic number 6, atomic weight 12.01115. Manganese (Mn): Manganese is a brittle, metallic element that exists in the ore of pyrolusite. When making steel, it reacts with sulfur and helps to ...

was less than the atomic mass (average mass of the atom). For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass ...

The term ‘weighted mean mass’ takes into account the different contribution of each isotope to the overall mass. Relative atomic mass is not the same as mass number. Mass numbers close mass ...

For example, the atomic number of sodium is 11. Every sodium atom has 11 protons and 11 electrons. It has 11 positive charges and 11 negative charges. The mass number of an atom is its total ...

Aluminum is a metal in group IIIA of the periodic table with atomic number 13, an atomic weight of 26.982, and a density of 2.70. It has a melting temperature of 660 C. The electronic configuration of ...