In their work astrophysicists deal with large distances between stars, and galaxies, and the size of the universe. These are written in sci. notation. Elementary particle physicists deal with extremely small particles, atoms, protons, bosons, etc. These masses and sizes are written in sci. notation.
Scientific notation is used to compute very large or very small numbers.
It usually isn't. Scientific notation is used for very large and very small numbers, that are not normally used in your daily life. Unless your "daily life" involves work in science or engineering.
You use scientific notation when it comes to "too large" or "too small" numbers. The reasons why using scientific notation is useful are that it saves time to do the computation and also that it makes people's life easier to compute values instead of writing them out completely!
Of coarse!
Everday life
It is essential to write very small and very large numbers
To compute very large or very small numbers.
When working with really large or really small numbers.
how is petrol used in our everday life
neon lighting
a door
Most people do not.