Electrons are notably smaller than nucleons (protons and neutrons), however, they have an equal amount of charge to protons. This is why an atom with the same amount of protons as electrons is considered electrically neutral.

The nucleus itself is positively charged, as the electrons are located relatively far away from the atomic center.

A nucleon is defined as a particle that is found in the nucleus of an atom. The nucleus is composed of proton particles and neutron particles. These are densely bound together to form a nucleus; thus, these two subatomic particles are nucleons.

Electrons are found in a wide radius outside the nucleus, and are not considered nucleons.

The experiment that confirms the atom structure is Rutherford's gold foil experiment. In the experiment, alpha particles were directed toward a thin piece of gold foil and reflected radiation was detected. The result of the experiment showed very little reflection, and most of the radiation passed straight through the foil. The conclusion drawn was that the majority of atomic volume consists of a loose electron cloud, and only a small region is occupied by a dense nucleus capable of reflecting the alpha radiation.

Electrons are located in an electron cloud, which surrounds a densely packed center known as the nucleus. The nucleus is composed of protons and neutrons. Note that the valence shell contains electrons, but only refers to the region of the electron cloud farthest from the nucleus.

The experiment that confirms the atom structure is Rutherford's gold foil experiment. In the experiment, alpha particles were directed toward a thin piece of gold foil and reflected radiation was detected. The result of the experiment showed very little reflection, and most of the radiation passed straight through the foil. The conclusion drawn was that the majority of atomic volume consists of a loose electron cloud, and only a small region is occupied by a dense nucleus capable of reflecting the alpha radiation.

All of the given statements are true.

Protons and neutrons are found in the atom's nucleus. The number of protons is the factor used to identify an atomic element, while the number of neutrons contributes to the overall atomic mass and isotopic identity. Electrons are found in the electron cloud and have negligible mass (significantly less than protons or neutrons). Protons are positively charged, while electrons are negatively charged, creating an attraction force.

Neutrons have no charge. Electrons have a charge of  and protons have a charge of .

Protons and neutrons are found in the nucleus of atoms, while electrons are found in orbitals around the nucleus.

First, start off by finding S (sulfur) on the periodic table. According to the period table, the atomic number for sulfur is 16. That means that sulfur (in it's uncharged, unionized state) has 16 protons, and 16 electrons. Since this ion has a negative two charge, we know it has picked up two extra electrons. Thus  contains 18 electrons.

A diatomic element is an element that will spontaneously bond with itself if it isn't already part of a compound. This is done to increase stability. The seven diatomic elements are hydrogen, oxygen, nitrogen, fluorine, chlorine, bromine, and iodine. Note that all of these except iodine are gasses at room temperature. Helium is a noble gas, which means it has a full valence shell. Helium does not need to bind to anything to increase its stability.

An atom's valence electrons are the electrons on the outermost shell surrounding the atom. For the first shell, the number of valence electrons can be at most 2. For all subsequent shells, the maximum is 8. To determine the number of valence electrons around a neutral atom, you match the atom with its group number. As you can see from the picture below, fluorine has a group number of 7. Therefore, it has 7 valence electrons.