Changing the number of protons, such as by adding 1 proton (option a), alters the element in the electron configuration, as the atomic number uniquely defines an element.
The correct answer is option A.
The identity of an element is determined by its atomic number, which is the number of protons in the nucleus. Therefore, any change to the number of protons would alter the element represented in the electron configuration.
In the given scenario, there is 1 proton in the nucleus. If we add 1 proton (option a), the atomic number increases by 1, changing the element. The number of protons uniquely defines an element, and any alteration to this count results in a different chemical species.
Conversely, adding 1 electron (option b) does not change the identity of the element. Electrons contribute to the charge and behavior of the atom but do not determine the element itself. The same holds true for adding 1 neutron (option c) – neutrons contribute to the mass but not the identity.
Removing the electron (option d) would also change the overall charge of the atom, making it a positively charged ion, but the fundamental identity of the element remains the same as long as the number of protons is unchanged.
Therefore , from the given options the correct one is A.