Chemistry Basics Quiz

Chemistry is the study of matter and its interactions with energy. It encompasses fields such as biochemistry, physical chemistry, organic chemistry, analytical chemistry, polymer chemistry, materials science, forensic chemistry, nuclear chemistry, astrochemistry, geochemistry, and environmental chemistry. Atoms make up elements, which combine through chemical bonds to form compounds like molecules—the building blocks of everything around us.

Atomic structure refers to how atoms are built within their nucleus and electron shells. The atomic number describes the number of protons in an atom's nucleus, while the mass number includes both protons and neutrons. Hydrogen has one proton, and all other atoms have at least two electrons. Electron shells have different energies; when they gain energy from outside sources like light, food, or electricity, electrons move into higher levels and release energy. This movement releases heat and light, making things hotter or brighter.

The Periodic Table contains every element discovered so far, organized by increasing atomic weight. Each row represents a period, showing patterns between neighboring elements. For example, hydrogen occupies a column to itself, lithium is next on the left side of the table, then beryllium, boron, carbon, nitrogen, oxygen, fluorine, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, tin, lead, radon, polonium, astatine, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, radon, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and lawrencium.

Chemists often work with solutions containing solutes dissolved in solvents. Solutions can conduct heat or charge, affecting the phase changes of substances near them, causing reactions called precipitations. Inorganic chemistry studies nonliving materials without carbon chains and organic chemistry focuses on living organisms made mostly of carbon.

Reactions occur whenever chemicals mix and interact with each other because the reactants want to reach a more stable state—a lower energy level where there aren't any missing or extra pieces. Reactions fall into five main types: combination, decomposition, single displacement, double displacement, and combustion. Combination involves combining simple substances to make new complex ones, decomposing splits apart big complicated substances back into simpler ones, single displacement replaces one substance with another, and double displacement exchanges substances. Double displacement also makes salts, which are ionic compounds that dissolve easily in water.