The positively charged part at the centre of an atom is called as :

Explanation

The positively charged part at the centre of an atom is called the nucleus. The nucleus is the central core of the atom. In the nucleus, protons and neutrons are present and are called nucleons. A proton is a positively charged particle, and a neutron is neutral; therefore, the nucleus is positively charged. The mass of protons and neutrons (approximately the same) is $1.67 \times 10^{-27}$ kg, and their discoveries are attributed to E. Goldstein and James Chadwick, respectively.