Two chemical bonds unite three atoms into a molecule. which types of bonds are they?

This type of bonds would be the covalent bonds.

Explanation:

The type of bonds that are made by the sharing of electrons is known as covalent bonds.

For example, A water molecule consists of two hydrogen atoms and a single oxygen atom. Each hydrogen has a single electron whereas oxygen has six electrons in its outermost shell. So, each hydrogen atom shares its electron with the oxygen atom. As a result, each hydrogen gets the required two electrons and oxygen gets eight electrons in its outermost shell.    

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.