Question

The elements A [At. No. 2] has atomic mass 4. Write the number of protons, number of electrons, and electronic configuration of the element and hence, state whether the elements is noble gases and why

Answer 1

Given,

Atomic number = 2

Mass number = 2

Step 1: Calculating the number of protons and electrons

Atomic number of an element is equal to the number of protons or the number of electrons present in the neutral state of that atom.

Atomic number	Number of electrons	Number of protons
2	2	2

Step 2: Electronic configuration

The electronic configuration is the distribution of electrons in the given shell or orbitals of an atom is known as electronic configuration

Uses of electronic configuration:

It also helps to predict whether the elements are metal,non-metal, metalloid, and noble gas

• If there is 1,2,3 electron in their outermost shell then generally it is metal except, H, He, B
• If there is 4,5,6,7 electron in their outermost shell then generally it is non-metal
• If there is 2[He], 8 electron in their outermost shell then generally it is a noble gas.

Electronic configuration of given element: 2

Hence, it is a noble gas.

Thus, the number of proton of element A is 2, the number of electrons of A element is 2, and the electronic configuration of the element A is 2, and this is a noble gas