Atomic Structure Key Vocabulary

Key Vocabulary in Chemistry

Atomic Structure

• Atom: The smallest unit of matter that retains the properties of an element
• Element: A substance consisting of atoms with the same number of protons in the nucleus
• Proton: A positively charged subatomic particle found in the nucleus of an atom
• Neutron: A neutral subatomic particle found in the nucleus of an atom
• Electron: A negatively charged subatomic particle found in orbitals around the nucleus of an atom
• Nucleus: The central part of an atom containing protons and neutrons

Chemical Bonding

• Chemical bond: A force that holds two or more atoms together
• Molecule: A group of atoms bonded together
• Ion: An atom or group of atoms with an electric charge
• Valence electron: An electron in the outermost energy level of an atom, involved in bonding
• Covalent bond: A bond formed by sharing one or more pairs of valence electrons
• Ionic bond: A bond formed by the transfer of electrons, resulting in ions with opposite charges

Chemical Reactions

• Chemical reaction: A process in which one or more substances are converted into new substances
• Reactant: A substance that is consumed during a chemical reaction
• Product: A substance formed during a chemical reaction
• Catalyst: A substance that speeds up a chemical reaction without being consumed
• Activation energy: The minimum energy required for a chemical reaction to occur

Chemical Properties

• Physical property: A characteristic of a substance that can be observed without changing its chemical composition
• Chemical property: A characteristic of a substance that can be observed only through a chemical change
• Acid: A substance that donates a proton (H+ ion)
• Base: A substance that accepts a proton (H+ ion)
• pH: A measure of the concentration of hydrogen ions in a solution

Atomic Structure

• An atom is the smallest unit of matter that retains the properties of an element, which has atoms with the same number of protons in the nucleus.
• A proton is a positively charged subatomic particle found in the nucleus of an atom.
• A neutron is a neutral subatomic particle found in the nucleus of an atom.
• An electron is a negatively charged subatomic particle found in orbitals around the nucleus of an atom.
• The nucleus is the central part of an atom containing protons and neutrons.

Chemical Bonding

• A chemical bond is a force that holds two or more atoms together, forming a molecule.
• An ion is an atom or group of atoms with an electric charge.
• Valence electrons are electrons in the outermost energy level of an atom, involved in bonding.
• A covalent bond is a bond formed by sharing one or more pairs of valence electrons.
• An ionic bond is a bond formed by the transfer of electrons, resulting in ions with opposite charges.

Chemical Reactions

• A chemical reaction is a process in which one or more substances are converted into new substances, involving reactants and forming products.
• A catalyst is a substance that speeds up a chemical reaction without being consumed.
• Activation energy is the minimum energy required for a chemical reaction to occur.

Chemical Properties

• A physical property is a characteristic of a substance that can be observed without changing its chemical composition.
• A chemical property is a characteristic of a substance that can be observed only through a chemical change.
• An acid is a substance that donates a proton (H+ ion).
• A base is a substance that accepts a proton (H+ ion).
• pH is a measure of the concentration of hydrogen ions in a solution.