Final answer:
The nucleus of an atom is composed of protons and neutrons, with protons being positively charged and neutrons being neutral. Electrons, which are negatively charged, orbit the nucleus.
Step-by-step explanation:
The composition of the nucleus of an atom is a fundamental concept in chemistry and physics. The nucleus is the dense, central core of the atom and is composed of two types of subatomic particles: protons and neutrons. Protons carry a positive electric charge, while neutrons are electrically neutral. These particles are tightly packed together in the nucleus, with protons giving the nucleus a positive charge. Outside the nucleus, the atom consists of negatively charged particles called electrons that orbit the nucleus. For instance, the nucleus of a carbon atom is made up of six protons and six neutrons, whereas a simple hydrogen atom's nucleus has just one proton and no neutrons.
In the context of the question about the composition of the atomic nucleus, the correct answer is B) It is composed of protons and neutrons.