Select the correct answer from the answers in brackets to complete each sentence.

1. An element has electronic configuration 2, 8, 1 and 12 neutrons. Its mass no. is …………… [11/23/12]
2. The maximum number of electrons in M-shell is …………… [8/32/18]
3. Isotopes have same …………… [no. of neutrons / electronic configuration / atomic masses].
4. An …………… [atom/ion] is capable of independent existence in solution.
5. An atom with electronic configuration 2, 7 and mass number 19 will have …………… neutrons. [8/10/12]

1. An element has electronic configuration 2, 8, 1 and 12 neutrons. It's mass no. is 23.
2. The maximum number of electrons in M-shell is 18.
3. Isotopes have same electronic configuration.
4. An ion is capable of independent existence in solution.
5. An atom with electronic configuration 2, 7 and mass number 19 will have 10 neutrons.