Atoms with five, six or seven valance electrons gain electrons to complete the octet because it is more convenient for the atoms to gain three, two or one electron as compared to lose five, six or seven electrons. Thus atoms with five, six or seven valance electrons form negative ions by gaining electrons.
Atoms with one, two or three valance electrons lose the electrons to get complete octet because it is more convenient for the atoms to lose one two or three electrons as compared to gain the seven, six or five electrons. The atoms with one, two or three valance electrons form positive ions.
Photosynthesis is the process where by plants manufacture their own food through conversion of carbon(iv)oxide and water in presence to sunlight to produce glucose and oxygen as by product.
The reaction is photo-catalyzed and would only take place in the presence of sunlight.
