Answer:
a) ΔE = 1.5 eV , b) n=∞, c) n= 3
Step-by-step explanation:
a) the energy of the transition is the energy difference between the two states 
 ΔE = E₂ –E₁ 
 ΔE = 0 - (-1.5) 
 ΔE = 1.5 eV 
b) The energy of each state is given by the equation 
 E = -13.606 / n² 
The highest quantum number is 
 n = √ (13,606 / E) 
 n = √ (13.606 /1.5) 
 n = 3
 
the transition is n = ∞ that has energy 0
 
c) the lowest quantum number is 3