"A particle that consists of a nucleus of protons and neutrons surrounded by an electromagnetically-bound cloud of electrons."
The study of the composition, properties, and behavior of atoms.
The history of atomic theory: The development of atomic theory from ancient philosophy to modern science.
The fundamental particles of atoms: Protons, neutrons, and electrons, their properties, and their interactions.
The structure of atoms: Atomic models, electron configurations, orbitals, and energy levels.
The periodic table: The arrangement of elements based on their atomic structure, trends in atomic and physical properties, and periodicity.
Chemical bonds: The interaction between atoms to form molecules and compounds, including covalent, ionic, and metallic bonding.
Quantum mechanics: The mathematical description of the behavior of particles at the atomic and subatomic level.
Spectroscopy: The study of the interaction between matter and electromagnetic radiation, including atomic and molecular spectroscopy.
X-ray crystallography: The use of X-ray diffraction to study the three-dimensional structure of molecules.
Nuclear chemistry: The study of nuclear reactions, radioactive decay, and isotopes.
Applications of atomic theory: The use of atomic theory in fields such as materials science, biochemistry, and nanotechnology.
Crystalline structures: Characterized by a repeating pattern of atoms or molecules that are arranged in a specific way. This can refer to metallic or non-metallic crystals, such as diamond, quartz, or aluminum.
Polymorphic structures: Substances that can exist in different structures, such as carbon. Carbon can exist in different forms, including diamond, graphite, and fullerenes.
Amorphous structures: Solids that do not have a regularly repeating pattern, such as glass.
Liquid crystal structures: Substances that have an intermediate phase between a solid and a liquid. These molecules are organized in a particular direction and can conduct electricity.
Molecular structures: Organic molecules that can have a wide range of structures, from linear chains to complex three-dimensional shapes.
Metallic structures: Characterized by closely packed atoms or ions that are held together by metallic bonds. This type of atomic structure provides metals with their unique properties, such as malleability and ductility.
"The chemical elements are distinguished from each other by the number of protons that are in their atoms."
"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."
"Atoms are so small that accurately predicting their behavior using classical physics is not possible due to quantum effects."
"Typically around 100 picometers across."
"More than 99.94%."
"If the numbers of protons and electrons are equal, as they normally are, then the atom is electrically neutral."
"If it has more protons than electrons, it has a positive charge, and is called a positive ion (or cation)."
"If an atom has more electrons than protons, then it has an overall negative charge, and is called a negative ion (or anion)."
"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."
"The nuclear force is usually stronger than the electromagnetic force."
"When the repelling electromagnetic force becomes stronger than the nuclear force."
"The nucleus splits and leaves behind different elements."
"Chemical bonds to form chemical compounds such as molecules or crystals."
"The ability of atoms to attach and detach from each other."
"Chemistry is the discipline that studies these changes."
"A nucleus of protons and neutrons."
"If any are present, have no electric charge."