Which of the following has the maximum number of neutrons?

The nucleus of the element $_{21}E^{45}$ contains

Which of the following particles has more electrons than neutrons?

Which of the following pairs involves isoelectronic ions?

State whether the following statements are true or false:
$(i)$ Isobars have different atomic numbers.
$(ii)$ $_{14}^{30}\text{Si}$,$_{16}^{32}\text{S}$ are isotones.
$(iii)$ Niels Bohr was the first to suggest that the atom is spherical.
$(iv)$ Rutherford's model is accepted as the nuclear model of the atom.

Match the following species with the correct number of electrons present in them:

Species	Number of Electrons
$(i) Be^{2+}$	$(a) 0$
$(ii) H^{+}$	$(b) 10$
$(iii) Na^{+}$	$(c) 2$
$(iv) Mg^{+}$	$(d) 11$