An atom is the smallest constituent unit of an element that retains the properties of that element.

The three fundamental subatomic particles are: protons (positively charged), neutrons (neutral), and electrons (negatively charged).

The atomic number is the number of protons in the nucleus of an atom. It is unique for each element and determines its chemical properties.

The mass number is the sum of the number of protons and neutrons in the nucleus of an atom. It determines the isotope of an element.

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

The Bohr model describes the atom as a small, positively charged nucleus surrounded by orbiting electrons in discrete energy levels or shells.

A chemical change involves the formation of new substances with different properties, while a physical change involves a change in the form or state of a substance without altering its chemical composition.

A chemical reaction is a process that involves the rearrangement of atoms or molecules to form new substances with different properties.

The five main types of chemical reactions are: synthesis, decomposition, single displacement, double displacement, and combustion.

A balanced chemical equation represents a chemical reaction using the reactants' and products' chemical formulas, with the number of atoms of each element being equal on both sides.

A catalyst is a substance that increases the rate of a chemical reaction without being consumed or altered in the process.

An endothermic reaction absorbs heat energy from the surroundings, while an exothermic reaction releases heat energy to the surroundings.

The limiting reagent is the reactant that is completely consumed in a chemical reaction, thus limiting the amount of product that can be formed.

Titration is a laboratory technique used to determine the concentration of a known solution by slowly adding a solution of known concentration until a chemical reaction is completed.

A centrifuge is a laboratory equipment used to separate mixtures based on the density of the components by spinning the mixture at high speeds.

A fume hood is a ventilated enclosure used in laboratories to prevent exposure to hazardous or toxic fumes, vapors, or particulates.

In an ionic compound, electrons are transferred between atoms, forming positively and negatively charged ions held together by electrostatic forces. In a covalent compound, atoms share electrons through covalent bonds.

In a solid, particles are closely packed and vibrate in fixed positions. In a liquid, particles are close together but can slide past each other. In a gas, particles are far apart and move freely in random motions.

The periodic table is a tabular arrangement of the chemical elements organized by increasing atomic number and grouped by similar chemical properties. It is a fundamental tool for understanding and predicting the properties of elements and compounds.

An element is a pure substance that cannot be broken down into simpler substances by chemical means, while a compound is a substance made up of two or more different elements chemically combined.

The law of conservation of mass states that the total mass of the reactants in a chemical reaction is equal to the total mass of the products, meaning mass is neither created nor destroyed during a chemical reaction.

A mole is a unit that represents the amount of a substance containing the same number of particles (atoms, molecules, or ions) as there are atoms in 12 grams of carbon-12. It is a convenient way to measure and relate the masses of different substances.

A strong acid completely dissociates into its constituent ions in an aqueous solution, while a weak acid only partially dissociates, leaving some undissociated molecules.

A buffer solution is an aqueous solution that resists changes in pH upon the addition of small amounts of an acid or base. It is used to maintain a relatively stable pH in various chemical and biological systems.

Indicators are substances that change color at specific pH values and are used in acid-base titrations to determine the endpoint of the reaction, which is the point at which the reaction is complete.

Oxidation is the loss of electrons by a substance, while reduction is the gain of electrons by a substance. These two processes always occur together in a redox (reduction-oxidation) reaction.

A burette is a graduated glass tube used in a laboratory to accurately dispense or measure the volume of a liquid, especially in titrations.

Qualitative analysis determines the presence or absence of specific substances, while quantitative analysis determines the amount or concentration of a substance present in a sample.

The molar mass of a substance is the mass of one mole of that substance, expressed in grams per mole. It is used to convert between the mass and the amount of a substance in moles.

A saturated solution is a solution that contains the maximum amount of dissolved solute at a given temperature and pressure. An unsaturated solution can still dissolve more solute.

A strong electrolyte completely dissociates into ions when dissolved in water, while a weak electrolyte only partially dissociates, with some molecules remaining undissociated.

A desiccator is a sealable container used to store and protect hygroscopic (moisture-absorbing) materials by maintaining a dry environment through the use of desiccants.

An endothermic process absorbs heat energy from the surroundings, while an exothermic process releases heat energy to the surroundings.

A crucible is a heat-resistant container used in laboratories for various high-temperature processes, such as heating, melting, or calcining substances.

A homogeneous mixture is a mixture in which the composition is uniform throughout, while a heterogeneous mixture is a mixture that consists of visibly different substances or phases.

A physical property is a characteristic of a substance that can be observed or measured without changing its chemical composition, while a chemical property is a characteristic that describes the substance's ability to undergo chemical changes or reactions.

A pipette is a calibrated glass or plastic tube used in laboratories to accurately measure and transfer small volumes of liquids.

A solvent is the substance present in the greater amount in a solution, and it is the dissolving medium. A solute is the substance present in the lesser amount, which is dissolved in the solvent.

A reversible reaction is a chemical reaction that can proceed in both the forward and reverse directions, while an irreversible reaction is a chemical reaction that essentially proceeds in only one direction.

A separatory funnel is a piece of laboratory equipment used to separate and isolate the components of a mixture of two immiscible (non-mixing) liquids based on their differences in density.

A hot plate is a heating device used in laboratories to heat substances or solutions in containers placed on its surface, often for processes like evaporation, melting, or chemical reactions.

According to the Arrhenius theory, an acid is a substance that dissociates in water to produce hydrogen ions (H+), while a base is a substance that dissociates in water to produce hydroxide ions (OH-).

A watch glass is a small, circular glass dish used in laboratories for various purposes, such as holding and evaporating small amounts of liquids, weighing solids, or covering beakers and other containers.

A precipitate is a solid that forms from a solution and settles at the bottom, while a supernatant is the liquid layer remaining above the precipitate after a precipitation reaction or centrifugation.

A reflux condenser is a piece of laboratory glassware used to cool and condense vapors during a heating process, allowing the condensed liquid to flow back into the reaction vessel, preventing the loss of volatile components.

According to the Lewis theory, a Lewis acid is a species that accepts a pair of electrons, while a Lewis base is a species that donates a pair of electrons to form a covalent bond.

A magnetic stirrer is a device used in laboratories to create a rotating magnetic field that causes a magnetic stir bar immersed in a solution to spin, allowing for efficient mixing or agitation of the solution.