### Theory:

1. For the most common elements like non-metals, we use the first letter of the English name.

 Element Symbol Element Symbol Boron $$B$$ Oxygen $$O$$ Carbon $$C$$ Phosphorus $$P$$ Fluorine $$F$$ Sulphur $$S$$ Hydrogen $$H$$ Vanadium $$V$$ Iodine $$I$$ Uranium $$U$$ Nitrogen $$N$$ Yttrium $$Y$$

2. If the name of an element has the same letter as another, use the first and second letter of English name. First letter in upper case and the second letter in lower case.

 Element Symbol Element Symbol Aluminium $$Al$$ Gallium $$Ga$$ Barium $$B$$ Helium $$He$$ Beryllium $$Be$$ Lithium $$Li$$ Bismuth $$Bi$$ Neon $$Ne$$ Bromine $$Br$$ Silicon $$Si$$ Cobalt $$Co$$ Argon $$Ar$$

3. If the first letter or first two letters of an element is the same as another, use the first and second or third letter of English name that they do not have in common.

 Element Symbol Element Symbol Argon $$Ar$$ Calcium $$Ca$$ Arsenic $$As$$ Cadmium $$Cd$$ Chlorine $$Cl$$ Magnesium $$Mg$$ Chromium $$Cr$$ Manganese $$Mn$$ Bromine $$Br$$ Silicon $$Si$$ Cobalt $$Co$$

4. Some elements use old or Latin name of the elements. There are eleven such elements.

 Element's name Latin name Symbol Sodium Natrium $$Na$$ Potassium Kalium $$P$$ Iron Ferrum $$Fe$$ Copper Cupuram $$Co$$ Silver Argentum $$Ag$$ Gold Aurum $$Au$$ Mercury Hydrargyrum $$Hg$$ Lead Plumbum $$Pb$$ Tin Stannum $$Sn$$ Antimony Stibium $$Sb$$ Tungsten Wolfram $$W$$

5. Some of the elements are named using the name of country, or scientist, or colour, or mythological character, or planet.

 Name Symbol Name derived from Americium $$Am$$ America (country) Europium $$Eu$$ Europe (country) Nobelium $$No$$ Alfred Nobel (Scientist) Iodine $$I$$ Violent (colour, Greek) Mercury $$Hg$$ God Mercury (mythologic character) Plutonium $$Pu$$ Pluto (planet) Neptunium $$Np$$ Neptune (planet) Uranium $$U$$ Uranus (planet)

Writing the symbols:

1. If an element has a single English letter as a symbol, it should be written in upper case.

Example:

$$H$$ - Hydrogen
$$B$$ - Boron

2. If an element has a two-letter symbol, the first letter should be written in the upper case and the second letter in lower case.

Example:

$$Ca$$ - Calcium
$$Ni$$ - Nickel

The symbol of an element signifies,
• Name of the element.
• One atom of the element.
Example:

The symbol "$$O$$" refers the element of oxygen, i.e., one atom of oxygen.
Reference:
file:///C:/Users/user/Desktop/Books/8th_Science/TN/8th_Std_Term_I_Science_EM.pdf