An atom is the smallest unit of matter that still retains the distinctive properties of an element. It is composed of a nucleus containing protons and neutrons, with electrons orbiting around it.

Sodium is represented by the symbol 'Na', which comes from its Latin name 'Natrium'. This symbol is universally recognized in the periodic table.

The atomic number is defined as the number of protons in an element's nucleus. It uniquely identifies an element and is fundamental in determining its chemical behavior.

A compound is formed when two or more elements bond chemically in fixed proportions. Its properties are distinct from those of the individual elements that compose it.

Electrons carry a negative charge, which is essential in the formation of chemical bonds and interactions. In contrast, protons are positively charged and neutrons have no charge.

The periodic table is organized in order of increasing atomic numbers, which dictates the recurring chemical properties of the elements. This systematic arrangement reveals periodic trends among the elements.

The notation 2p❴ specifically means that in the second energy level, the p subshell contains 4 electrons. This detail helps in understanding the electron distribution which influences chemical reactivity.

Isotopes are forms of the same element that have equal numbers of protons but differ in the number of neutrons. This results in different mass numbers while retaining the element's chemical identity.

A balanced chemical equation has the same number of atoms for each element on both sides of the equation. In '2H₂ + O₂ → 2H₂O', the hydrogen and oxygen atoms are conserved, making it balanced.

The mole concept provides a bridge between the atomic scale and macroscopic amounts of material. It allows chemists to count entities like atoms and molecules by relating mass measurements to a fixed number of particles.

Covalent bonds form when atoms share pairs of electrons to achieve a more stable electron configuration. This mode of bonding is common in organic molecules and many inorganic substances.

Reaction rates are influenced by factors such as temperature, concentration, and catalysts. The color of a solution does not inherently affect how quickly a reaction proceeds.

A catalyst provides an alternative reaction pathway with a lower activation energy, thereby increasing the reaction rate without being consumed. It does not alter the overall energy change of the reaction.

Acids are characterized by their ability to donate protons (H❺) when dissolved in water, increasing the hydrogen ion concentration. This proton-donating property is fundamental to acid behavior.

A chemical reaction involves breaking existing bonds and forming new ones, resulting in substances with different properties. In contrast, physical changes only alter the state or appearance without changing chemical composition.

The stoichiometric ratio for the reaction is 2 moles of A for every 3 moles of B. With 4 moles of A requiring exactly 6 moles of B, both reactants are present in the correct ratio, so neither is limiting.

Percent yield is a measure of the efficiency of a reaction calculated by dividing the actual yield by the theoretical yield. Multiplying this ratio by 100 converts it to a percentage.

According to VSEPR theory, a molecule with four electron domains and no lone pairs adopts a tetrahedral geometry to minimize repulsion. This arrangement is common in molecules like methane (CH₄).

To assign oxidation states, chemists use standard rules and the known oxidation numbers of common elements. The sum of the oxidation states must equal the overall charge of the compound, ensuring charge balance.

Ionic bonds form when electrons are transferred between atoms, resulting in oppositely charged ions held together by electrostatic forces. Conversely, covalent bonds form when atoms share electrons to achieve stable electron configurations.