Questions

Optical illusion is what that refers to persistence of vision with a principle that multiple images blend into a single image in human mind and what is showed in cinema.

Hence, Persistence of vision is the principle behind cinema.

In a brief, the system software is the interface between the hardware and user applications. System software is a type of computer program that is designed to run a computer’s hardware and application programs.

Examples : OS, System utilities, BIOS like mouse, keyboard, hard disc, Device drivers, Assembler,...

Improving muscular strength and endurance slows bone density loss.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

B.R. Ambedkar