Sodium
The element we decided to tell you about was sodium. ... The element sodium is a soft, silver-colored metal, waxlike at room temperature but breakable as the temperature falls. ... Sodium is a member of the alkali metals, a family that includes lithium, potassium, rubidium, cesium, and francium. PROPERTIES Sodium is a soft metal, and its easy to cut with a knife. ... Sodium has only one stable isotope, mass number 23. Sodium reacts easily with a large variety of elements and compounds by acting as a reducing agent, and it reacts by giving up ,or losing, an electron. The tendency to do so is so strong that sodium can replace hydrogen from water. ... Sodium forms compounds in which its valence is +1. HISTORY Compounds of sodium were known and used during ancient times, but the highly reactive nature of the element prevented its preparation as a pure substance until 1807.