List the three subatomic particles that compose atoms and give the basic properties (mass and charge) of each.

Protons are fundamental components of all atoms, acting as one of the main building blocks of matter. In any element, the number of protons within the atomic nucleus determines the identity of the element; this is known as the atomic number. Interestingly, the number of protons is also what gives elements their unique properties. As positively charged particles, protons have a relative charge of +1, which is balanced by the equal but opposite charge of electrons in a neutral atom.
With a mass roughly 1,836 times that of an electron, protons are relatively heavy and contribute significantly to the atomic mass of an element. Each proton is approximately 1 atomic mass unit (amu), this unit being a standard measure for atom and molecule masses. The presence and interaction of protons within the nucleus play a critical role in the stability and behavior of atoms.

Neutrons share the atomic nucleus with protons and are essential for the stability of most atoms. They have no electrical charge and thus are neutral, which is fundamental for the stability of the nucleus as they mitigate the electrostatic repulsion between positively charged protons. Neutrons are roughly the same mass as protons, close to 1 atomic mass unit. However, the actual mass can slightly exceed that of protons, but this small difference is often disregarded at a basic level.
Because they are electrically neutral, they do not influence the electrical properties of an atom or molecule. They do, however, add to the total mass, hence the term 'isotope' refers to atoms with the same number of protons but varying numbers of neutrons. The unique ratio of neutrons to protons is what can give each isotope different stability and nuclear properties.

Electrons are the very light, negatively charged particles that exist in the regions around the atomic nucleus, which are known as electron clouds or orbitals. Their relative charge is -1, exactly opposite that of a proton. Despite their charge, their mass is significantly lower compared to protons and neutrons, with a relative mass about 1/1836 amu, making their contribution to the total atomic mass almost negligible. However, their presence and arrangement around the nucleus are crucial since they determine the atom's chemical behavior, reactivity, and bonding with other atoms. Electrons are involved in forming chemical bonds, and their movement and transitions between different energy levels can result in the absorption or emission of light, a principle that underlies spectroscopy and the colorful displays of light we often associate with different chemical reactions and compounds.

The atomic nucleus is the dense central core of an atom where protons and neutrons reside. This minuscule area contains the bulk of an atom's mass, as the subatomic particles that compose it—protons and neutrons—are each approximately 1 atomic mass unit. The nucleus is held together by a strong nuclear force, one of the four fundamental forces of nature, which overcomes the repulsion between the positively charged protons.
Discoveries like that of the atomic nucleus have been pivotal in understanding the nature of atoms and consequently the composition of matter. The behavior and characteristics of the nucleus play a decisive role in phenomena such as radioactivity, nuclear fission, and fusion, which have profound implications in energy production, medical diagnostics, and scientific research.

The electron cloud is a term used to describe the region where electrons are likely to be found orbiting the atomic nucleus. This region is defined by complex shapes known as orbitals, each with varying probability distributions where an electron is likely to be located at any given time. Unlike the well-defined orbits of planets around the sun, electron positions cannot be pinpointed to an exact location; rather, we think of them in terms of areas of high probability.
Understanding the electron cloud is fundamental to grasp concepts like the arrangement of electrons in atomic and molecular orbitals, the principles of chemical bonding, electron configurations, and the resulting properties of substances. Valence electrons, the electrons in the outermost shell of the electron cloud, are particularly crucial as they are the ones involved in chemical reactions and bonding.

The atomic mass unit (amu) is a standard unit of mass used to express the masses of atoms and subatomic particles. It is defined as one-twelfth of the mass of an unbound neutral carbon-12 atom in its ground state which equals approximately 1.66053906660 x 10^-27 kilograms. Each proton and neutron has a mass close to 1 amu, thereby providing a convenient scale for describing atomic and subatomic mass.
When calculating the mass of atoms or molecules, the sum of the masses of protons, neutrons, and electrons typically constitute the total atomic or molecular mass. However, because electrons have so much less mass compared to protons and neutrons, their contribution is often considered negligible when determining the atomic mass of an element.

The relative charge of particles refers to the charge they carry compared to the charge of a proton, which is considered as the standard positive charge (+1). This concept is especially important when talking about the subatomic particles in an atom. Protons carry a positive charge of +1, which balances the negative charge of -1 from electrons. Neutrons, as their name suggests, are neutral and do not carry any charge.
Understanding the relative charge is crucial for understanding the nature of chemical bonding, as the attractions and repulsions between these charges govern the interactions between atoms. The balance of positive and negative charges in an atom determines its electrical neutrality or ionization state, which in turn, influences the atom's behavior in the presence of other atoms and the formation of molecules.