The electronegativity of nitrogen (N) is 3.0, while the electronegativity of hydrogen (H) is 2.1. As it can be seen that nitrogen (N) is more electronegative than that of hydrogen (H),
So electron pairs are attracted towards nitrogen and thus it carries a partial negative charge and hydrogen carries a partial positive charge. The image of electron distribution is attached as follows.
Thus NH₃ is a polar molecule .
solution:
You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. 
<em><u />the correct option is <u>c ) 10,000...</u>
an acid which is more acidic than 6 pH will be of pH 5 acid because if one acid is stronger than the other acid than its magnitude of strength is 1000... it is constant always...</em>
Cyclohexane - cyclic hydrocarbon with 6 carbon atoms.
2 methyl groups (-CH3) on carbon atom number 1
Hope it helped!
