Question

 

1) how would the 2nd ionization energy of Mg compare to the 1st ionization energy of Na?

2) Which Element in Group 15 has the most metallic character

3) Calculate the frequency ( in Hz) and energy (in J) of 760 nm light.

 

Answer 1

Ans 1 - It does not take so much enregy from Na (Sodium) to form Na⁺ as it has 3S¹ in last shell but in case of Mg its 1st ionisation will be soo high because Mg has 3S² in its last shell hence we know that it is very stable configration so we need very high energy to form Mg⁺ and we know that secong ionisation energy is more than first because it requires more energy to remove electron from positively charged ion.

Ans 2 - From going right to left in periodic table in group metallic character increases that means group 1 has more metallic character than group 15 and going top to botton in periodic table matellic character increases So by this logic we can say that Bismuth (Bi) has most metallic character than other elements in group 15.

Ans 3 - We can use formula C= to find frequency ,

As C = speed of light (3.0 x 10⁸m/s)

= wave length =  = 760 nm = 7.6x10^-7 m

= frequency

= 3 x 10⁸ (m/s)/ 7.6x10^-7 m

= 3.947 x 10¹⁴ s^-1

for energy -

E = hv

h=6.626 x 10^-34 J s

v = 3.947 x 10¹⁴ s^-1

E = 6.626 x 10^-34 J s  x 3.947 x 10¹⁴ s^-1

E = 2.615 x 10^-19 J