X has been used to represent love and kisses for centuries. But how did it start?
While the origins of the cross as a kiss are still debated, the answer likely lies in the letters of working-class lovers like these.
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Symbols and formulae
We call these letters symbols. And an element is a pure substance made from only one type of atom. And there are quite a lot of elements. There are something like 100, and each has a unique symbol ...