Which element is represented by the symbol 'O' in the periodic table?

The element represented by the symbol 'O' in the periodic table is oxygen. This is because each element has a unique one- or two-letter symbol, which is usually derived from its English or Latin name. In this case, oxygen is a vital element that is essential for life on Earth; it is necessary for respiration in many organisms and plays a crucial role in various chemical reactions, including combustion and oxidation processes.

The other options represent different elements with their own unique symbols: osmium has the symbol 'Os,' oganesson is represented by 'Og,' and gold is denoted by 'Au.' Knowing the correct symbols for each element is fundamental in chemistry and helps in understanding the composition of matter.