What is the order of velocity of $\alpha$-particles?

Is there any difference between an electron and $\beta$-particle?

For which of the following radiations is the path not affected by electric field and why?

$\alpha$-rays, $\beta$-rays, $\gamma$-rays.

Which have greater ionising power; $\alpha$-particles or $\beta$-particles?

Write down the following radiations in the order of increasing penetrating power:

X-rays, gamma rays and ultraviolet light.