Each element has a shorthand symbol
The word “hydrogen” has 8 letters, which is kinda long. So scientists, being scientists who like to make things as simple as possible, decided to shorten it to just one letter. What letter would you choose? The obvious choice for hydrogen is “H” because it’s the first letter of its name. Likewise, the symbol for carbon is C, for nitrogen is N, for oxygen is O and for uranium is U. How easy is that!
The shorthand way of writing an element is called its symbol. You can think of a symbol as the element’s nickname, or perhaps its nickletter.
What letter would you choose for helium?
We can’t use “H” because this has already been taken by hydrogen. So scientists give helium two letters, “He”, to make it different to hydrogen. All symbols are either one or two letters. Usually an element’s symbol comes from the first one or two letters of its English name.
If the symbol has 2 letters, then the 1st letter is always upper case, and the 2nd letter is always lower case. It’s wrong to write helium’s symbol as HE, or hE or he! Only He is correct. Each element is only allowed one capital letter.
A symbol’s 1st letter is always upper case, and the 2nd letter is always lower case.
Here are some symbols to confuse you. The symbol Co stands for the element cobalt. But CO must be two elements, because there are two capital letters. CO stands for the compound carbon monoxide with is made with both the elements carbon and oxygen.
What is the symbol for gold?
It should be G or Go, right? Wrong!
Instead, the symbol for gold is Au. This symbol is taken from the Latin name for gold, which is “aurum”, which refers to the golden glow before dawn. So not all elements are named after the English name for the element. Some are even named after places (francium), or people (einsteinium) or planets (mercury). Can you think of others?
The symbol for silver is Ag, after its Latin name, “argentum”. The symbol for iron is Fe, after its Latin name “ferrum”, for mercury is Hg, after the Latin word “hydrargyrum” meaning “silver water”. And the symbol for lead is Pb, after its Latin name, “plumbum”. How embarrassing!