Matter: States, Elements, and Compounds

Chemistry is the study of matter and its properties, including how matter changes.

States of Matter

• Solids have a definite shape and volume, exemplified by ice, rock, and wood, and are used in construction, art, and tools.
• Liquids possess a definite volume but assume the shape of their container; examples include water, oil, and blood, serving as solvents, lubricants, and in biological systems.
• Gases lack a definite shape or volume, expanding to fill their container, such as air, helium, and steam, and find use in industrial processes, weather balloons, and power generation.
• Plasma is an ionized gas with high energy, seen in lightning, stars, and neon signs, and is applied in fusion research, plasma TVs, and industrial processes.

Chemical Elements and Compounds

• An element is a pure substance with atoms having the same number of protons, like gold (Au), oxygen (O), and carbon (C), used in jewelry, medicine, and electronics.
• A compound consists of two or more elements chemically bonded in a fixed ratio, such as water (H2O), salt (NaCl), and methane (CH4), used in drinking, cooking, and as fuels.

Chemical Reactions

• Acid-Base Reactions occur between an acid and a base, forming a salt and water, exemplified by hydrochloric acid (HCl) reacting with sodium hydroxide (NaOH), used in titrations, spill neutralization, and industrial processes.
• Redox Reactions involve electron transfer between chemical species, like combustion and rusting, utilized in batteries, corrosion prevention, and metabolism.
• Precipitation Reactions involve two soluble salts combining to form an insoluble salt (precipitate), such as silver nitrate (AgNO3) with sodium chloride (NaCl) forming silver chloride (AgCl), which is used in wastewater treatment, pigment production, and qualitative analysis.

Organic Chemistry

• Alkanes are saturated hydrocarbons with single bonds, including methane, ethane, and propane, used as fuels and solvents.
• Alkenes are unsaturated hydrocarbons with at least one double bond, like ethene (ethylene) and propene (propylene), used in plastics production.
• Alcohols contain a hydroxyl (-OH) group, such as ethanol and methanol, used as solvents, fuels, and disinfectants.
• Carboxylic Acids contain a carboxyl (-COOH) group, like acetic acid (vinegar) and citric acid, used in food preservation, cleaning, and pharmaceuticals.

Polymers

• Polymers consist of large molecules with repeating structural units (monomers).
• Polyethylene (PE) is a thermoplastic from ethylene monomers, used in plastic bags, bottles, and films.
• Polyvinyl Chloride (PVC) is a thermoplastic from vinyl chloride monomers, used in pipes, siding, and flooring.
• Polystyrene (PS) is a thermoplastic from styrene monomers, used in packaging, insulation, and disposable cups.
• Nylon is a synthetic polyamide polymer used in textiles, ropes, and automotive parts.

Biochemistry

• Carbohydrates are organic compounds of carbon, hydrogen, and oxygen, often with the formula Cx(H2O)y, for example, glucose, fructose, and starch, used as energy sources, structural components, and in food.
• Proteins are complex biomolecules of amino acids, such as enzymes, antibodies, and structural proteins, acting as catalysts, immune defenses, and tissue structure.
• Lipids encompass fats, oils, waxes, and certain vitamins, for instance, triglycerides, phospholipids, and cholesterol, used for energy storage, cell membrane structure, and hormone production.
• Nucleic Acids are polymers of nucleotide monomers, like DNA and RNA, storing and transmitting genetic information.

Analytical Chemistry

• Titration determines a solution's concentration, used in quality control, environmental monitoring, and chemical research.
• Spectroscopy studies matter's interaction with electromagnetic radiation to identify substances, determine concentrations, and study structures.
• Chromatography separates mixture components, used in drug testing, environmental analysis, and chemical synthesis.
• Mass Spectrometry measures the mass-to-charge ratio of ions to identify unknown compounds, quantify known compounds, and determine the structure and chemical properties of molecules.

Thermochemistry

• Exothermic Reactions release heat, such as combustion and acid-base reactions, used in heating systems and power generation.
• Endothermic Reactions absorb heat, such as melting ice and baking soda with vinegar, used in cold packs and chemical processes.