- "An atom is a particle that consists of a nucleus of protons and neutrons surrounded by an electromagnetically-bound cloud of electrons."
The basic unit of matter, consisting of a nucleus of protons and neutrons, surrounded by electrons.
Atomic Structure: The structure of atoms, including the location, charge, and mass of subatomic particles such as protons, neutrons, and electrons.
Isotopes: Atoms of the same element that have different numbers of neutrons in their nucleus.
Atomic Mass: The mass of an atom, which is determined by the number of protons and neutrons in its nucleus.
Electron Configuration: The arrangement of electrons in an atom's energy levels, which determines the atom's properties and behavior.
Periodic Table: A chart that arranges all known elements in order of their atomic number and chemical properties.
Chemical Bonding: The formation of chemical compounds through the sharing and/or transfer of electrons between atoms.
States of Matter: The physical forms that matter can exist in, including solids, liquids, and gases.
Thermodynamics: The study of the relationship between heat, energy, and work.
Kinetic Theory: The theory that explains the behavior of gases in terms of their particles' motion and collisions.
Quantum Mechanics: The study of quantum phenomena that occur at the atomic and subatomic levels.
Nuclear Chemistry: The study of the behavior of atomic nuclei, including radioactivity and nuclear reactions.
Atomic Spectra: The unique patterns of light that are emitted or absorbed by atoms when they undergo transitions between energy levels.
Electron Configuration and the Periodic Table: The correlation between an element's location on the periodic table and the electron configuration of its atoms.
Chemical Reactions: The process by which atoms or groups of atoms are rearranged to form new substances.
Chemical Equations: The symbolic representation of a chemical reaction, including the reactants, products, and stoichiometry.
Avogadro's Law: The principle that equal volumes of gases at the same temperature and pressure contain the same number of molecules.
Ideal Gas Law: An equation that relates the pressure, volume, temperature, and number of molecules of an ideal gas.
Acid-Base Chemistry: The study of the behavior of acids and bases in chemical reactions.
Solutions and Solubility: The properties of substances that dissolve in liquids to form homogeneous mixtures.
Electrochemistry: The study of the relationship between electricity and chemical reactions.
Hydrogen: The lightest and smallest atom, it has only one proton and one electron.
Helium: The second lightest element, it has two protons and two electrons.
Carbon: A fundamental element in organic chemistry and life, it has six protons and six electrons.
Nitrogen: An essential component of proteins and DNA, it has seven protons and seven electrons.
Oxygen: A critical component of the atmosphere and essential for respiratory metabolism, it has eight protons and eight electrons.
Iron: A transition metal that is essential for hemoglobin and energy transport, it has 26 protons and 26 electrons.
Uranium: A radioactive metal that is used in nuclear power generation, it has 92 protons and 92 electrons.
Electrons: Negatively charged particles that surround the nucleus of an atom, they determine an element’s chemical properties.
Protons: Positively charged particles that are found in the nucleus of an atom, they determine the atomic number of an element.
Neutrons: Neutral particles that are also found in the nucleus of an atom, they determine an element’s isotopic properties.
- "The chemical elements are distinguished from each other by the number of protons that are in their atoms."
- "Any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper."
- "The number of neutrons defines the isotope of the element."
- "Atoms are so small that accurately predicting their behavior using classical physics is not possible due to quantum effects."
- "More than 99.94% of an atom's mass is in the nucleus."
- "Each proton has a positive electric charge, while each electron has a negative charge, and the neutrons, if any are present, have no electric charge."
- "If the numbers of protons and electrons are equal, as they normally are, then the atom is electrically neutral."
- "If an atom has more electrons than protons, then it has an overall negative charge, and is called a negative ion (or anion)."
- "Conversely, if it has more protons than electrons, it has a positive charge and is called a positive ion (or cation)."
- "The electrons of an atom are attracted to the protons in an atomic nucleus by the electromagnetic force. The protons and neutrons in the nucleus are attracted to each other by the nuclear force."
- "Under certain circumstances, the repelling electromagnetic force becomes stronger than the nuclear force."
- "In this case, the nucleus splits and leaves behind different elements. This is a form of nuclear decay."
- "Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds."
- "such as molecules or crystals."
- "The ability of atoms to attach and detach from each other is responsible for most of the physical changes observed in nature."
- "Chemistry is the discipline that studies these changes."