Q. 2. Observe the following diagram and write the answers. ER NA a, Identify the clerrient. b. How many electrons are there c. Namne the second shell of the atom, d. How many electrons are there in this shell ?
Answers
Answer:
In an atom, the electrons surround the nucleus in different orbitals or energy levels. These orbitals are known as either first, second, third ... energy levels or K,L,M, N... shells. K-shell is the first energy level and can have a maximum of 2 electrons. L-shell is the second energy level and can have a maximum of 8 electrons. M-shell is the third energy level and can have a maximum of 8 electrons.
Explanation:
The atomic number of an element is 20. Atomic number is equal to the number of electrons present in a neutral atom. Thus, the element with atomic number 20 has 20 electrons. Out of 20 electrons, 2 electrons are present in the K-shell and 8 electrons are present in the L-shell. Out of the remaining 20-(2+8)=10 electrons, 8 electrons are present in the M-shell and 2 electrons are present in the N shell.
Hence, 8 electrons are present in the M-shell of an element with atomic number 20.
