Science

Chemical Reaction

A fundamental process in chemistry where reactants transform into products through the breaking and forming of chemical bonds, often altering the molecular structure.

Valency

An essential concept in chemistry representing the combining capacity of an element, indicating how many atoms of that element can participate in bonding with other elements.

Balanced Equation

A clear representation of a chemical reaction where the quantity of each type of atom is conserved, ensuring that the number of reactants equals the number of products.

Physical Change

A transformation in which a substance changes its form, state, or appearance without altering its chemical composition, such as melting ice or boiling water.

Chemical Change

A process that leads to the formation of one or more new substances with different chemical properties, exemplified by rusting iron or burning wood.

Acid

A type of chemical that, when dissolved in water, increases the concentration of hydrogen ions (H⁺), often characterized by a sour taste and the ability to turn blue litmus paper red.

Base

A chemical substance that, upon dissolution in water, produces hydroxide ions (OH⁻) and is usually characterized by a bitter taste and slippery feel, turning red litmus paper blue.

Neutralization Reaction

A chemical process in which an acid and a base react together to form salt and water, effectively balancing the pH levels.

Synthesis Reaction

A specific type of chemical reaction where two or more reactants combine to form a single, more complex product, as seen in the formation of water from hydrogen and oxygen.

Decomposition Reaction

A reaction in which a single compound breaks down into two or more simpler substances, often requiring energy input, such as heat or electricity.

Single Displacement Reaction

A chemical reaction where one element displaces another in a compound, resulting in a new element and a new compound.

Double Displacement Reaction

A reaction involving the exchange of ions between two compounds, forming two new compounds, often seen in precipitation reactions.

Redox Reaction

A type of chemical reaction that involves the transfer of electrons between two species, where one agent is oxidized and another is reduced.

Criss-Cross Rule

A systematic approach used to determine the chemical formula of ionic compounds by swapping the charges of the ions to balance the overall charge.

Catalyst

A substance that speeds up a chemical reaction by lowering the activation energy without being consumed or permanently altered in the process.

Inhibitor

A chemical agent that slows down or stops a chemical reaction, often used in various industrial and biochemical processes to control reaction rates.

Globalization in Chemistry

The influence and role of chemical processes and research on global challenges, focusing on sustainable solutions like renewable energy and pollution prevention.

Ion

An electrically charged particle that is formed when an atom or molecule gains or loses one or more electrons, resulting in a positive or negative charge.

Cation

A type of ion with a positive charge, created when an atom loses one or more electrons during chemical reactions.

Anion

A type of ion with a negative charge, formed when an atom gains one or more electrons, resulting in an excess of electrons.

Periodic Table

A systematic arrangement of chemical elements, organized by increasing atomic number, which provides insight into their properties, including reactivity and atomic structure.

Molecule

A group of two or more atoms bonded together, which can represent elements or compounds.

Compound

A substance formed when two or more different elements are chemically bonded in a fixed ratio.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons, influencing bond formation.

Endothermic Reaction

A type of chemical reaction that absorbs heat from the surroundings, usually resulting in a temperature drop.

Exothermic Reaction

A chemical reaction that releases heat to its surroundings, often causing an increase in temperature.

pH Scale

A logarithmic scale used to measure the acidity or alkalinity of a solution, ranging from 0 (acidic) to 14 (basic).

Solvent

A substance that dissolves a solute, resulting in a solution, commonly found in liquid form like water.

Solute

The substance that is dissolved in a solvent to form a solution, present in lesser amount compared to the solvent.