Chemical symbols and simple formulas – basics
How it works
Chemical symbols are internationally defined abbreviations for chemical elements, for example H for hydrogen, O for oxygen and Fe for iron. A chemical formula shows which elements are present in a substance and in what numerical ratio they are present. In molecules, the subscript indicates how many atoms of an element are contained, for example in H₂O: 2 hydrogen atoms and 1 oxygen atom. In salts such as NaCl, the formula shows the smallest whole-number ratio of the types of particles. Chemical formulas are not equations of reactions, but describe the composition of a substance.
The chemical symbol stands for an element. A chemical formula shows which elements are contained in a substance and in what numerical ratio they occur. Subscript numbers indicate, in molecules, the number of atoms of the respective element.
An example
Which chemical symbol stands for the element oxygen?
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Chemistry. The topic assignment may vary by federal state.