Why do we use symbols on
the periodic table

this lesson you learned that a chemical symbol is a shorthand way to represent an element and that each element on the periodic table has a unique chemical symbol. Chemical symbols are used to standardize the 'language of chemistry' and to identify elements and atoms in a chemical formula easily.23-Dec-2015

The periodic table is a classification system for the elements. ... The symbols are abbreviations of the origins of the word for each element. For example, the origin of lead's symbol, Pb, is the Latin word 'plumbum' meaning 'liquid silver'. The number above the symbol is the atomic mass (or atomic weight).

Explanation:

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2

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.