Page 24 - Curriculum Visions Dynamic Book

Sm see Samarium; Sn see Tin Sodium (Na)
Element 11. A soft, silvery-white metal in group 1 (the alkali metals) in the Periodic Table.
Sodium is the most common alkali metal and the sixth most abundant element on Earth. It is most frequently found as the compound sodium chloride – common salt.
Sodium metal is very reactive. It easily ignites in air. It reacts vigorously with water to release hydrogen (which then may catch fire).
Sodium is widely used to make chemicals and also for yellow sodium vapour lamps. Sodium will form
an alloy with potassium.
The cut surface of the sodium pellet has a shiny surface that tarnishes very quickly.
Discovery
Sodium was one of many elements discovered by Sir Humphry Davy during his experiments with electricity. He found sodium in 1807 during the electrical separation (electrolysis) of molten sodium hydroxide, NaOH. Sodium was collected at the cathode.
Key facts...
Name: sodium
Symbol: Na
Atomic number: 11
Atomic weight: 22.98
Position in Periodic Table: group 1 (1)
(alkali metal); period 3
State at room temperature: solid
Colour: silvery-white
Density of solid: 0.97 g/cc
Hardness: 0.5
Melting point: 98°C
Boiling point: 883°C
Origin of name: a combination of the English
word soda and the Latin word for soda, natrium. The symbol Na comes from the first two letters of natrium.
Shell pattern of electrons: 2–8–1
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