mass

Empirical Knowledge

Knowledge obtained through investigation and observations.

Theoretical Knowledge

Knowledge that explains scientific observations.

Matter

Anything that has mass and occupies space.

Theory

An explanation based on observation, experimentation, and reasoning.

Atoms

Fundamental particles that make up matter.

Democritus

Proposed that matter is made up of indivisible particles called atoms.

Aristotle

Proposed the four elements model of matter.

John Dalton

Proposed the Billiard Ball Model of the atom.

J.J

Discovered the electron and proposed the Plum Pudding Model.

Ernest Rutherford

Discovered the proton and performed the gold foil experiment.

James Chadwick

Discovered the neutron and explained the overall mass of the atom.

Neils Bohr

Proposed the planetary model of the atom and the concept of energy levels.

Isotopes

Atoms of the same element with different numbers of neutrons.

Lewis Symbol

Representation of an element with dots for valence electrons.

Octet Rule

Atoms tend to achieve 8 valence electrons.

Ion

Charged entity formed by gaining or losing electrons.

Cation

Positively charged ion.

Anion

Negatively charged ion.

Lone Pair

A pair of electrons that are not involved in bonding and are localized on a single atom.

Molecule

Particles formed when two or more atoms bond covalently to achieve a full valence shell of electrons.

Lewis Structure

Diagrams that show the bonding between atoms and lone pairs of electrons in a molecule. shared electron pairs are shown as lines and unshared electrons are shown as dots

Octet Rule

Atoms tend to bond in such a way that they have a full valence shell of eight electrons.

Electronegativity

The ability of an atom to attract bonding electrons to its self (rizz)

Ionic Bond

A bond formed between atoms with an electronegativity difference greater than 1.7.

Covalent Bond

A bond formed between atoms with an electronegativity difference less than 1.7.

Polar Covalent Bond

A covalent bond where electrons are not shared equally, leading to partial positive and negative charges.

Dipole Moment

The measure of molecular polarity due to an uneven distribution of electrons in a molecule.

Intermolecular Forces

Weak forces of attraction between molecules that affect physical properties like melting points and solubility.

Repulsion between shared/lone electron pairs

The concept that lone electron pairs can repel bond pair electrons.

Metallic

Metals pass valence electrons among each other, leading to good electrical conductivity and the existence of positive ions.

London dispersion force

A weak attractive force between all entities, including non-polar molecules and unbonded atoms, due to temporary electron imbalances.

Electron

a particle with a negative charge

Neutrons

Unchanged subatomic particle (with the nuclei)

Proton

a particle that is positively charged (with the nucleus, held by an electrical attraction)

Nucleons

electrons, protons, neutrons collected together

Atomic number

Number of protons represented as “Z” ( Z = p^+ ( = e- for a neutral atom))

Mass Number

The sum of protons and neutrons represented as “A”

Z

The number of protons you have

A

The atomic Mass. the sum of protons and neutrons (p+ + n0) or (Z + n0)

Period

A row in the periodic table

Group

Column of elements in the periodic table; sometimes reffered to as a family

Period Law

the elements arranged in order of increasing atomic number, showing properties of periodic recurrence and gradual change.

Main group elements

Group 1, 2, 13, 14, 15, 16, 17 ,18

Lewis symbol

representation of the element with the valence electrons surrounding represented as dots

Octet rule

when atoms combine, they tend to achieve 8 valence electrons

Ion

Charged atom (monatomic) or molecule (polyatomic ion)

Cation

A positively charged ion formed by the removal of one or more electrons from the valence shell of a neutral atom

What does “charged” mean

The proton does not equal the electrons

Anion

a negatively charged ion formed by gaining one or more electrons

Polyatomic

consisting of Multiple atoms

Monatomic

Consisting of ONE atom

valence

the capacity of an atom determined by the number of electrons that it will lose, add or share when it reacts with other atoms

atomic radius

the measurement of the size of an atom, expressed in picometres (pm) the distance from the center of an atom to the outermost electrons

effective nuclear charge

The force experienced by an electron in an atom due to the positively charged nucleus

Ionic Radius

The measurement of the size of an ion

Ionization energy

The amount of energy needed to remove a single valence electron from an atom or ion in the gaseous state.

Electron affinity

The energy changed that occurs when an electron is added to a neutral atom in the gaseous state

Chemical Bond

The force of attraction holding two atoms or ions together in a compound

electrolyte

A solution dissolved in water that has the ability to conduct electricity

Formula Unit

A small repeating unit in an ionic crystal

Ionic compound

A pure substance composed of positively charged ions and negatively charged ions in a fixed ratio

Molecular element

A pure substance composed of two or more atoms of the same element (O2)

Diatomic

Made up of two atoms

Molecular compound

Pure substance composed of molecules made of up two or more non-metallic elements

Covalent bond

The attractive force or bond that results from the sharing of an electron pair

Bonding electron

An electron in the valence shell of an atom that is available to form a covalent bond with another atom

Bonding capacity

The number of covalent bonds that an atom can form

Lone pair

Pairs of electrons that are not involved in bonding

Structural Formula

A representation of the number, types, and arrangement of atoms in a molecule, with dashes representing covalent bonds

Electronegativity (ΔEN)

The difference in electronegativities of two bonded atoms or ions

non-polar covalent Bond

A covalent bond formed between atoms with identical (or very similar) electronegativities

Polar Covalent bond

A covalent bond formed between atoms with significantly different electronegativities resulting in a bond with localized positive and negative charges or pols

Binary Ionic compound

A compound that - consists of ions of only two elements

Polyatomic ionic compound

a compound that consists of ions of more than two elements

Oxyanion

a negatively charged polyatomic ion that contains oxygen

Zero-sum rule

The sum of the positive charges equals the sum of the negative charges in an ionic compound

Hydrate

An ionic compound that contains water as part of its crystal structure

Petrochemical

A compound manufactured from a fossil fuel

Upcycling

The process of converting an industrial material or product into something of similar or greater value

Polar Molecule

A molecule in which the uneven distribution of electrons results in a positive charge at one end and a negative charge at the other end

Non-polar molecule

A molecule in which the electrons are equally distributed among the atoms, resulting in no localized charges

Intermolecular force

the attractive force between molecules

Dipole-Dipole Force

An intermolecular force of attraction that forms between slightly positive end of one polar molecule and the slightly negative end of an adjacent polar molecule

London Dispersion Force

A weak attraction force acting between all entities, including non-polar molecules and unbonded atoms, caused by the temporary imbalance of electrons within entities

Van Der Waals Forces

The weak forces of attraction between molecules including dipole-dipole forces and London dispersion forces

Hydrogen Bond

an unusually strong dipole-dipole force between a hydrogen atom attached to a highly electronegative atom (N. O, or F) and a highly electronegative atom in another molecule

Surface tension

A phenomenon, caused by forces of attraction between moleculessss that leads to the formation of a skin-like film on the surface of a liquid