When creating a mixture, what is the substance that is the most plentiful?

In homogeneous mixture the substance which is present in large quantity is called Solvent.

Explanation:

Mixture : It is the combination of two or more substances.The substances of the mixture can be separated by physical process.

There are two types of mixture :

1.Homogeneous Mixture : The mixture which has uniform composition throughout .E.g Salt + Water mixture , Soft drink water.

Solute : The Substance that is present in less amount in a mixture is called solute.In Salt + Water mixture, Salt is the solute.

Solvent : The substance which is present in large amount is called Solvent.In Salt + Water mixture, water is the solvent.

2.Heterogeneous Mixture:

The mixture which have non-uniform composition throughout. E.g Salt + water mixture , Chalk+ water

you need to give more information

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.