Answer:
The law of reflection states that the angle of incidence and the angle of reflection are always equal.
The answer is 9. Calcium nitrate is made up
of 3 different elements that equal 9 atoms.
Polar bonds are formed between atoms of different electronegativities.
Answer:

Explanation:
Using the expression for the photoelectric effect as:

Also, 

Applying the equation as:

Where,
h is Plank's constant having value 
c is the speed of light having value 
is the wavelength of the light being bombarded
Given, 
is the binding energy or threshold energy
is the kinetic energy of the electron emitted. = 
Thus, applying values as:




