What is the difference between a chemical symbol and a chemical formula?​

A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements. Many elements have symbols that derive from the Latin name for the element

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

a:

by the combination of an unlimited number of elements