Which amongst the following is incorrect statement?

(1) ${\mathrm{C}}_2=\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)$
      C₂ molecule has 4 electrons in its two degenerate $\mathrm{\pi }$ molecular orbitals.
(2) ${\mathrm{H}}_2^{+}=\mathrm{\sigma }1{\mathrm{s}}^1{\mathrm{H}}_2^{+}$ion has 1 electron.
(3) $\begin{array}{l}{\mathrm{O}}_2^{+}\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\right)\\ \left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)\left({\mathrm{\pi }}^{\ast }2{\mathrm{p}}_{\mathrm{x}}^1={\mathrm{\pi }}^{\ast }2{\mathrm{p}}_{\mathrm{y}}^0\right)\end{array}$
       ${\mathrm{O}}_2^{+}$is a paramagnetic
(4) $\begin{array}{l}{\mathrm{O}}_2^{+}=\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\right)\\ \left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)\left(\mathrm{\pi }\ast 2{\mathrm{p}}_{\mathrm{x}}^1=\mathrm{\pi }\ast 2{\mathrm{p}}_{\mathrm{y}}^0\right)\end{array}$
Bond order$=\frac{10-5}{2}=\frac{5}{2}=2.5$
$\begin{array}{l}{\mathrm{O}}_2=\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\right)\\ \left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)\left({\mathrm{\pi }}^{\ast }2{\mathrm{p}}_{\mathrm{x}}^1={\mathrm{\pi }}^{\ast }2{\mathrm{p}}_{\mathrm{y}}^0\right)\end{array}$
Bond order $=\frac{10-6}{2}=\frac{4}{2}=2$
$\begin{array}{l}{\mathrm{O}}_2^{-2}=\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\right)\\ \left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)\left(\mathrm{\pi }\ast 2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }\ast 2{\mathrm{p}}_{\mathrm{y}}^2\right)\end{array}$
Bond order  $=\frac{10-7}{2}=\frac{3}{2}=1.5$
$\begin{array}{l}{\mathrm{O}}_2^{-2}=\left(\mathrm{\sigma }1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 1{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }\ast 2{\mathrm{s}}^2\right)\left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\right)\\ \left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right)\left({\mathrm{\pi }}^{\ast }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }\ast 2{\mathrm{p}}_{\mathrm{y}}^2\right)\end{array}$
Bond order $=\frac{10-8}{2}=1$