Why do atoms form molecules? The quantum physics of chemical bonds explained

think about this the visible universe consists mostly of less than 100 naturally occurring elements yet there's an immense diversity and complexity reflected in not only the myriad of substances that can be found in the universe but also substances that can be found within your own body how is it that we can have a near boundless number of chemical substances with only about 100 relatively simple building blocks called atoms to work with this is because the naturally occurring atoms are rarely found alone they're mostly found in combinations with other atoms through the process of chemical bonding the combinations of chemicals and materials that can be built with these various combinations is so vast that it can give rise not only to the variety of phenomena that we can observe in the universe but also the complexity required to create life fuel for energy that we need consciousness that we enjoy and every other macro scale process that affects us why is the universe not full of just 100 different types of atoms floating around in a sea of dull monotony lucky as these atoms bond to form rich chemicals that have properties fundamentally different than the atoms comprising them why does this happen the answer to this important question lies in understanding the role that energy plays in the formation of molecules and its roots and where else but quantum mechanics that explanation is coming up right now some of the most important chemicals to us like the air we breathe consists not of individual atoms but molecules oxygen for example is not found in the air as individual oxygen atoms but it's o2 are two oxygen atoms bound together nitrogen is also found as n2 two nitrogen ions bound together water without which we could not survive is h2o two atoms of hydrogen combined with one oxygen atom why are atoms prevalent mostly as molecules the key to understanding why atoms link together is energy