Which of the following ions has a pseudo-noble-gas electron configuration?
a) ni+
b) fe2+
c) cu+
d) mn2+

ions have a "pseudo-noble-gas" electron configuration.

The ion with the electron configuration is known as Nobel gas. The nature of noble gas is that the cations in this electron configuration are stable.

The Pseudo-noble gas has the electron configuration as:

Since, ion has the same configuration. The example of Nobel gas is, both and are stable compounds. To form only the electron is removed leaving the electronic configuration.

gas

explanation:

smoke is the matter of a gas