why alkali metals are most suitable to photoelectric emmission,,,,,

Photoelectric effect is the phenomenon by which the electrons are ejected from the surface of the metal when a radiation of suitable frequency is used. 

 1)  Alkali metals have only one electron in there valence shell ,there electronic configuration is 3s¹ . They have very low ionization energy so it will be easy to eject the electron from the alkali metals .Thus they are suitable for this  effect.

alkali metal have 1 valence elecrton and can lose it easily to gain a stable configuration thus there theshold frequency and thus the work func is less and hence are most suitable 

among all metals alkali metals have certainly lesser work function than other metals.

Photoelectric effect is the phenomenon by which the electrons are ejected from the surface of the metal when a radiation of suitable frequency is used. 

 1)  Alkali metals have only one electron in there valence shell ,there electronic configuration is 3s¹ . They have very low ionization energy so it will be easy to eject the electron from the alkali metals .Thus they are suitable for this  effect.

2) For the ejection of electron a radiation of high energy is used that is of low wavelength but radio waves are of larger wavelength it means of  low energy . Thus radio waves are not suitable for this purpose.

3) Photoelectric effect takes place only when a light of suitable frequency is used that is a frequency greater than the threshold frequency is used , then only ejection of electron takes place . Thus this effect can not takes place at all the frequencies . 

4) The angular momentum can be calculated by the formula √l(l+1) h/2π, which you will study at your higher grade. So for the hydrogen atom l=0 , because it has 1s¹ electronic configuration and for s orbital the value of l=0 . Thus by putting this value in the formula we get zero value of angular momentum.

6) There are a large number of lines that occur in the hydrogen spectrum corresponding to the different value of the frequencies .

Due to the lack of time ,i am not able to answer all of your question. Please try to solve yourself if in case you face any problem ,please let me know so that i can provide you valuable help.

AS THIS ALKALI METALS HAS LARGE SIZE AND LESS IONISATION ENERGY THEY LOSE THEIR OUTERMOST ELECTRON EASILY.

PHOTOELECTRIC EFFECT MEANS EJECTION OF ELECTRONS FROM A METAL WHEN THEY EXPOSED TO SUNLIGHT.

SO,THESE ALKALI METALS ARE SUITABLE TO THIS PHOTOELECTRIC EFFECT.