Unit 1: Matter, Chemical Trends, and Chemical Bonding

This set of flashcards covers key vocabulary terms related to matter, chemical trends, and chemical bonding, providing definitions and essential concepts for understanding atomic structure and interactions.

Atom

The smallest particle of an element that still retains the identity and the property of that element.

Subatomic Particles

The three main particles that make up an atom: protons, neutrons, and electrons.

Atomic Number

The number of protons in the nucleus of an atom, which determines the chemical nature of the element.

Mass Number

The sum of the number of protons and the number of neutrons in an atom.

Isotope

Atoms of the same element with the same atomic number and number of protons, but different number of neutrons and atomic mass.

Radioisotope

An isotope that is unstable and decays, emitting radiation.

Valence Electrons

The electrons in the outermost shell of an atom that are involved in chemical bonding.

Electron Shells

Energy levels around the nucleus where electrons are found.

Ionization Energy

The amount of energy required to remove the outermost electron from an atom or ion.

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons.

Cation

A positively charged ion that forms when an atom loses one or more electrons.

Anion

A negatively charged ion that forms when an atom gains one or more electrons.

Diatomic Molecule

A molecule composed of two atoms, which can be of the same or different chemical elements.

Intermolecular Forces

Forces of attraction between molecules, which affect physical properties such as boiling and melting points.

Dipole

A molecule with a positive end and a negative end due to uneven electron distribution.

Lewis Dot Diagram

A diagram that shows the valence electrons in an atom using dots around the chemical symbol.

Hydrocarbon

A compound made up of hydrogen and carbon atoms.

Alkali Metals

Highly reactive metals found in Group 1 of the periodic table.

Noble Gases

Elements in Group 18 of the periodic table that are completely unreactive due to having a full valence shell.

Acid

A substance that increases the hydrogen ion concentration in a solution.

Base

A substance that increases the hydroxide ion concentration in a solution.

Hydrate

A compound that contains water molecules within its structure.