Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
Because that is the outer ring.
Because magnesium loses its electrons easily than aluminum
Answer : The total pressure at equilibrium is 0.350 atm
Solution : Given,
Initial pressure of
= 0.350 bar
= 0.016
The given equilibrium reaction is,

Initially 0.350 0 0
At equilibrium (0.350-2x) x x
The total pressure at equilibrium = 
Thus, the total pressure at equilibrium is 0.350 atm