Here's a breakdown:

* Transmutation is the process of changing one element into another.

* Nuclear bombardment involves firing a particle at the nucleus of an atom. This can cause changes within the nucleus, such as:

* Adding or removing protons: This directly changes the element, as the number of protons defines the element.

* Adding or removing neutrons: This changes the isotope of the element.

Examples of transmutation reactions:

* Nuclear fission: A heavy nucleus, like uranium, is bombarded with neutrons, causing it to split into lighter nuclei and release energy.

* Nuclear fusion: Two lighter nuclei, like hydrogen isotopes, are forced together to form a heavier nucleus, releasing energy.

Key point: Transmutation reactions are fundamentally about changing the identity of an atom by altering its nucleus.