What is this wave function in Chemical bonding? Was studying chemical bonding(Valence bond theory) but there came this topic called wave equation but  have not studied quantum mechanics,so finding hard to understand these terms.Please help!!!
$\Psi$ is the wavefunction describing an electron's motion.  $\Psi^2$ is the probability density function for the electron. $\Psi^2$ is usually interpreted as the probability of finding the electron at a given set of coordinates.

In the case that $\Psi$ is a complex function (in that it contains imaginary numbers and not that it is complicated, which it usually is), $\Psi^2$ is defined as the product of $\Psi$ with its complex conjugate: $\Psi \Psi^*=|\Psi|^2$ so that the probability density function contains only real numbers. 

Consider a simple case of $\Psi=a+bi$. The complex conjugate would be $\Psi^*=a-bi$.

$$\Psi \Psi^* = (a+bi)(a-bi)=a^2+b^2$$

Often the probability density function is normalized so that its integral over all space is 1 (i.e. there is 100% chance of finding the electron in all of space). In the equation below, $A$ is the normalization constant.

$$1=A \int_o^{2\pi} \int_0^{2 \pi} \int_o^\infty \Psi \Psi^* dr d\theta \phi$$