The symbol for potassium comes from the latin word for potassium, kalium. That is why the chemical symbol for potassium is .

The word for iron in latin is ferrum, thus, the chemical symbol for iron is  because of its latin name.

Remember, the number of protons is equal to the atomic number of the element. Look at the periodic table and find the element with atomic number 42, it corresponds to molybdenum.

Since atoms are neutral, the number of electrons must equal the number of protons (to balance the negative and positive charges). Thus the element with 17 electrons also has 17 protons. The number of protons is equal to the atomic number of the element. Use the periodic table to find the element with atomic number 17, chlorine. Note that ions are not neutral, thus they have unequal numbers of protons and electrons. Also, isotopes of the same element contain differing numbers of neutrons, which also affects the weight of the isotope.

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 .