Basic Chemistry

Matter

Anything that takes up space, has mass, and is found in the phyisical states of solids, liquids, and gas

Element

Substance composed of only one atom type

Molecule

Unit of two or more atoms joined by chemical bonds

Compound

Substances of two or ore elements joined by chemical bonds

Mixture

A combination of two or more substances that do not chemically bond, like sugar and salt

Atom

Smallest unit of matter that retains properties of an element that cannot be broken down, and is composed of subatomic particles

Neutron

Subatomic particle with no electrical charge

Protons

Subatomic particle with a positive charge

Electrons

Subatomic particle with a negative charge

Atomic Number

The number of protons for an element, which determines the element’s properties

Isotopes

Atoms of an element that have an extra neuron or more. The atomic number stays the same, but the atomic mass is different. This makes it radioactive.

The Rule of Eights

The first inner electron shell can hold 2 electrons, and the valence shell (outmost shell) can hold 8 electrons.

Kinetic Theory of Matter

Theory that all atoms and molecules are in constant random motion

Potential Energy

Stored energy with no change taking place yet.

Kinetic Energy

Energy currently causing a change.

Chemical Reactions

Changes in the chemical composition of matter by breaking existing bonds and forming new ones, which anable atoms to give up/acquire electrons in order to complete their valence shell.

Synthesis Reaction

Type of chemical reaction where atoms or molecules combine to form a product

Decomposition Reaction

Chemical reaction where molecules break down into smaller molecules or atoms

Exchange Reaction

Chemical reaction where molecules exchange constituent components, or swap partners.

Reversible Reaction

Chemical reaction where the product of previous reaction can revert to the orginal reactant. Can go forward or backward.

Chemical Equilibrium

The state of dynamic balance in which the rates of forward and reverse processes (reactions) are equal.

Reactions are written as

Balanced Equations

Ion

A charged atom or molecule, or any atom or molecule that has a charge

Anion

When an atom or molecule gains an electron, it becomes negatively charged, known as a

Cation

When an atom or molecule loses an electron, it becomes positively charged, known as a

Ionic Bond

An attraction between an anion and cation, or oppositely charged ions

Polyatomic Ion

An ion that has multiple atoms, or when molecules lose electrons

Ionic Compounds

Compounds (salts) that are formed by ionic bonds, like sodium chloride (table salt)

Covalent Bond

A bond where two atoms share one or more pairs of valence electrons

Covalent Bonds are strong than Ionic Bonds due to

The shared electrons counting as part of each atom’s valence shell, thus holding more energy

Single Covalent Bond

The sharing of one pair of valence electrons

Double Covalent Bond or Double Bond

The sharing of two pairs of valence electrons.

Electronegativity

An atom’s attraction for the electrons in a covalent bond. The more [term] it has, the more strongly it pulls shared electrons to itself. Is determined by the amount of valence electrons.

Polar Covalent Bond

A chemical bond in which one atom is more electronegative, thus the atoms don’t share electrons equally. Such as H₂O

Hydrogen Bond

A chemical bond that forms when a hydrogen atom covalently bonds to an electronegative atom that is attracted to another electronegative atom. Known as a very weak bond and constantly breaks and rejoins.