Question

3. mer How many electrons in an atom can have each of the following quantum designations! 2 fourth period and forbital C. -41-3m--12 d. 3p 4. (pt) Why does the size of atoms increase going down a group on the periodic table? 5. (pt) What is a quanta of energy? 6. (pt) How does an atom generate atomic emission spectra? 7. (pt) Rank the following in order of increasing first ionization energies Ge, K. C S and Si X (pt Give the number of valence electrons for the following elements P

Answer 1

Solution:

3) A) Fourth period and f orbital:

It means, n = 4 and f orbital

Therefore, in 4f orbital, there are total 14 electrons are accomodated.

B) n = 6

Total number of electrons = 2n2

= 2 x (6)^2 = 72 electrons

C) n =4 , l=3 , m=-1

l = 3 (f orbital)

n = 4 means 4 shell

Thus, 4f orbital

Again, m = -1 represents only one of the f subshell.

Thus, total number of electrons = 2

D) 3P5

n = 3

l = 1

Since, 5 electrons are filled in P subshell,

Hence,

Total number of electrons = 5

4) Atomic size decreaes down the group due to increase in the number of orbitals. Therefore, the force of attraction from nucleus decreases and causes an increase in size.

5) Quanta of energy is known as photonic energy. It is equal to hv.

E = h v

Where, h = planck constant

v = frequency

6) When an electron is excited from ground state to higher excited state and returns back by emmiting light energy, then we observe emmision spectrum.