Draw the structural formula of an alkane that has eight carbon atoms and only primary hydrogen atoms.

Answer : The structural formula of octane is shown below.

Explanation :

Structural formula : In the structural formula, the bonding and type of bonds which holds the atoms in molecule together are shown.

The basic rules for naming of organic compounds are :

First select the longest possible carbon chain.

A suffix '-ane' present at the end of the name represent the alkane group.

For the number of carbon atom, we use prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.

In the given hydrocarbon, the longest possible carbon chain number is 8 that means we add prefix 'oct' and suffix '-ane'. So, the name of given hydrocarbon will be, octane.

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.