Protons carry a positive charge and are located in the nucleus of an atom. Neutrons and electrons do not have a positive charge, making proton the correct answer.

The periodic table is arranged by increasing atomic number, which corresponds to the number of protons. This organization also reveals periodic trends in element properties.

A compound is a substance where two or more elements are chemically bonded in fixed proportions. Mixtures, on the other hand, are physical combinations without fixed ratios.

Balancing a chemical equation ensures that the number of atoms for each element is the same on both sides, adhering to the law of conservation of mass. This process does not determine energy changes or concentrations.

Sodium is represented by the symbol Na, which is derived from its Latin name 'natrium'. The other options do not correctly represent sodium.

The balanced equation shows a 1:1 mole ratio between H2 and H2O. Therefore, 4 moles of H2 will produce 4 moles of H2O.

Carbon dioxide (CO2) is composed of one carbon atom (≈12.01 g/mol) and two oxygen atoms (≈16.00 g/mol each), adding up to approximately 44.01 g/mol.

Covalent bonds are characterized by the sharing of electron pairs between atoms. Ionic bonds, by contrast, involve the transfer of electrons.

Oxidation is defined as the loss of electrons during a reaction, while reduction involves the gain of electrons. The other terms do not relate to electron transfer.

The Law of Definite Proportions specifies that a chemical compound is composed of the same elements in fixed ratios by mass. The other laws pertain to unrelated phenomena.

Sublimation is the process in which a substance transitions directly from a solid to a gas without passing through a liquid phase. This is seen in substances like dry ice.

A catalyst provides an alternative pathway with a lower activation energy, thus speeding up a reaction. It is not consumed in the process and does not alter the equilibrium constant.

Double displacement reactions involve the exchange of ions between reacting compounds, and can lead to the formation of a precipitate. The other reaction types do not typically result in ion exchange.

Molarity is the concentration measurement expressed as moles of solute per liter of solution. Molality, normality, and percent composition are defined differently.

The limiting reactant is the reactant that is completely consumed first, thereby limiting the formation of products. It determines the maximum yield of the reaction.

In an endothermic reaction, heat is absorbed, so adding more heat shifts the equilibrium toward the products side (right) to counteract the change. This is an application of Le Chatelier's Principle.

The angular momentum quantum number (l) determines the shape of an atomic orbital. The principal quantum number indicates the energy level, while the magnetic and spin quantum numbers relate to orbital orientation and electron spin, respectively.

Across a period, the increasing nuclear charge pulls electrons closer to the nucleus, resulting in a decrease in atomic radius. Additional electron shells are added in different periods rather than across a period.

Ionic compounds have high melting points because of the strong electrostatic attractions between positively and negatively charged ions. These forces require a significant amount of energy to break apart.

The equivalence point in a titration is reached when the moles of acid equal the moles of base, meaning they have reacted in stoichiometrically equivalent amounts. It is independent of the indicator's color change, which is only a visual cue.