Yes.
They have different numbers of valence electrons.
Safety is important in all workplaces - and for the same reason. Employees want to go home in the same state of health they had when they got to work. Safety supports that goal.
Isomers have different structures even though they have same compounds
Isomerism. The structures of the molecules are different even when the numbers of atoms are the same. Organic molecules are the most common examples of this. Compare n-butane and iso-butane same formula different structures. See link
True
Is their starting point the same ? Are they going in the same, or different, even opposite directions from there ?
Different countries - and even different cities within the same country - have different speed limits.
Yes, there are many different kinds of billing software. Many different kinds are used even within the same industry.
There is no "as a rule". Different countries - and even different cities within the same country - have different speed limits.
Why according to Darwin two different areas within same continent have different species?
No. They are two different families of fish. Even fish within the same genera can't always interbreed.
There are several different treatments for Adrenal disease in ferrets. Treatment options can be either surgery or medications (or both). Veterinarian costs can vary a lot, even within the same city.
You can get Plays from famecrowd's website, they deliver the Plays within the same day and they even have a tracking area for clients. Also they have different packages for it.
The habit or religious costume. There are many different varieties even within the same religious order. There would be different costumes(habits) for different occasions and applications, some being winter weight, etc.
Even within the same city, different switching offices may have different test numbers, and those test numbers are not generally made publicly available.
Similar but different. The function of the endoplasmic reticulum can vary greatly with cell type, and even within the same cell it can have different functions depending on whether it is rough or smooth.
Communication within a department. As opposed to Inter-department communication, which is one department communication with another department within an organization. This happens far less than it should for the same kinds of reasons people have difficulty communication: different goals, different points of view, different expectations, and even different vocabulary/acronyms.