Sodium is an alkali metal in group IA of the periodic table with atomic number 11, an atomic weight of 22.99, and a density of 0.97 Mg/m 3. Its melting point is 97.8 C, and it boils at 892 C. The ...

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 ...