Answer:
Electrons are far apart from the nucleus as we move down the group.
Explanation:
The ionization energy is the amount of energy which is necessary to remove an electron from an atom.
In an atom there exist a force of attraction at the center (nucleus). This is because of the positive charge which exists in the nucleus. This force of attraction is less felt as the distance between the electron and the proton increases. Hence the ionization energy increases as the number of shells increases for an atom. As we move down the group in the periodic table, the number of shells increases which implies a decrease in ionization energy.
<span>The scientists discovered that when they organized elements in order of increasing atomic mass there is a pattern of repetition of properties (A). The periodic law was developed by Dmitri Mendeleev and Lothar Mayer in 1869. They worked independently of each other and both created a periodic table. They both arranged the items on the table by weight and both suggested that certain properties of the elements recur. The Mendeleev table is the most important table because the values for the atomic mass are the most accurate.</span>
Answer:
4.823 x 10^-19 J
Explanation:
Energy is calculated by E = hv where h - Planck's constant in joule.s
v - frequency.
in this particular question the wave length is 4.12 x 10^-7 m. to exhaustively use this we need a relation between wave length & frequency. c=wv where C is approximately 3 x 10^8m/s
-v = c/w = 3x10^8m/s / 4.12 x 10^-7m = 7.28 x 10^14 Hz or 1/sec
now we can simply use Planck's constant in E=hv =
(6.626 x 10^-34) x (7.28 x 10^14Hz) = 4.823 x 10^-19 J.
