[ CHEM1010 ] Pre-Review

Matter

Anything that has mass and occupies space.

Mass

The amount of matter in an object.

Volume

The amount of space occupied by an object.

Density

The amount of mass per unit volume of a substance (ρ = m/V).

Physical Change

A characteristic that can be observed or measured without changing a substance's chemical identity.

Chemical Change

A characteristic that describes a substance's ability to undergo a chemical change.

Physical Change

A change that alters the form or state of a substance without changing its chemical composition.

Chemical Change

A change that produces one or more new substances with different chemical properties.

Element

A pure substance made of only one type of atom and cannot be broken down by chemical means.

Compound

A pure substance composed of two or more elements chemically bonded in fixed proportions.

Mixture

A combination of substances that are physically mixed but not chemically bonded.

Scientific Notation

A method of expressing very large or very small numbers using powers of ten.

Significant Figures

The digits in a measurement that indicate its precision.

Dimensional Analysis

A problem-solving method that uses conversion factors to convert one unit into another.

Atom

The smallest unit of an element that retains its chemical properties.

Proton

A positively charged subatomic particle found in the nucleus.

Neutron

A neutral subatomic particle found in the nucleus.

Electron

A negatively charged subatomic particle that occupies the space around the nucleus.

Atomic Number

The number of protons in the nucleus of an atom.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotope

Atoms of the same element that have different numbers of neutrons.

Ion

An atom or molecule that has gained or lost electrons and therefore has a net charge.

Cation

A positively charged ion formed by losing one or more electrons.

Anion

A negatively charged ion formed by gaining one or more electrons.

Valence Electrons

Electrons found in the outermost energy level of an atom that participate in chemical bonding.

Periodic Trends

Predictable patterns in the properties of elements across the periodic table.

Atomic Radius

A measure of the size of an atom from its nucleus to its outermost electrons.

Electronegativity

The tendency of an atom to attract shared electrons in a chemical bond.

Ionic Bond

A chemical bond formed through the transfer of electrons between atoms.

Covalent Bond

A chemical bond formed when atoms share one or more pairs of electrons.

Lewis Structure

A diagram that shows the arrangement of valence electrons and chemical bonds in a molecule.

VSEPR Theory

A theory used to predict the three-dimensional shape of molecules based on the repulsion between electron pairs.

Mole

The SI unit for the amount of substance, equal to 6.022 × 10²³ particles.

Avogadro's Number

The number 6.022 × 10²³, representing the number of particles in one mole.

Molar Mass

The mass of one mole of a substance, expressed in grams per mole (g/mol).

Balancing Chemical Equations

The process of adjusting coefficients in a chemical equation so that the number of each type of atom is the same on both sides.

Limiting Reactant

The reactant that is completely consumed first in a chemical reaction and determines the maximum amount of product formed.

Molarity

The concentration of a solution expressed as moles of solute per liter of solution (mol/L).

Oxidation

The loss of electrons during a chemical reaction.

Reduction

The gain of electrons during a chemical reaction.

Law of Conservation of Mass

The law stating that matter cannot be created or destroyed during a chemical reaction.

Synthesis Reaction

A reaction in which two or more substances combine to form a single product.

Decomposition Reaction

A reaction in which one compound breaks down into two or more simpler substances.

Redox Reaction

A chemical reaction involving the transfer of electrons between substances.

Solution

A homogeneous mixture in which one or more substances are dissolved in another.