Which elements are main-group elements?
1. Te
2. K
3. V
4. Re
5. Ag

Te

K

Explanation:

Main group elements are elements designated and located on the s-block and p-block on the periodic table. The core group or prominent elements are the elements that make up those groups. These groupings comprise the most naturally rich and abundant elements. The main group elements are those whose characteristics are more predicted as a function of their periodic table location. From the given options, only Te and K are elements of the main-group.

The Planck’s Equation states that

E = hv

E stands for energy measured in Joules

v stands for frequency measured in s^-1 or Hertz (Hz)- 1Hz .

h is Planck’s constant which is equivalent to 6.626x10-34 J.s

The Planck's equation states that the energy of a photon, is directly proportional to its frequency (v), by a constant factor (h).

Given:

E=3.2 * 10^-24 J

h= 6.626x10-34 J.s

Now we know that

E=hv

Thus substituting the given values we get

v=3.2 * 10^-24 /6.626x10-34

v=48 x 10^9 s^-1