Atoms, Elements, and Compounds: Properties of Matter and Atomic Theory

Comprehensive vocabulary flashcards covering the classification of matter, physical and chemical properties, atomic models, the periodic table, and chemical bonding from Chapters 5, 6, and 7.

Pure Substance

A type of matter that consists of only one type of particle.

Particle Theory of Matter

A theory describing the composition and behaviour of matter, stating that all matter is made up of tiny particles with empty spaces between them, in constant random motion, moving faster as temperature increases, and attracting one another.

Mixture

A substance that is made up of at least two different types of particles.

Mechanical Mixture

A mixture in which different types of matter can be distinguished visually, either with the unaided eye or with a microscope.

Solution

A uniform mixture of two or more substances in which the different types of particles cannot be distinguished visually.

Alloy

A solid solution composed of two or more metals.

Physical Property

A characteristic of a substance that can be determined without changing the composition of that substance.

Qualitative Property

A property of a substance that is not measured and does not have a numerical value, such as colour, odour, and texture.

Quantitative Property

A property of a substance that is measured and has a numerical value, such as temperature, height, and mass.

Lustre

A qualitative physical property describing the shininess or dullness of an object or substance.

Optical Clarity

The ability of a substance to allow light to pass through it, categorized as transparent, translucent, or opaque.

Brittleness

A physical property describing the breakability or flexibility of a substance when subjected to stress.

Viscosity

The degree to which a fluid resists flow, describing its ability to flow or pour readily.

Hardness

The relative ability of a substance to scratch or be scratched by another substance.

Malleability

The ability of a substance to be hammered into a thinner sheet or molded without shattering.

Ductility

The ability of a substance to be drawn or pulled into a finer strand or wire.

Electrical Conductivity

The ability of a substance to allow an electric current to pass through it.

Physical Change

A change in which the chemical composition of the substance remains unaltered and no new substances are produced.

Chemical Property

A characteristic of a substance that describes its ability to undergo changes to its composition to produce one or more new substances.

Chemical Change

A change in the starting substance or substances resulting in the rearrangement of components and the production of one or more new substances.

Precipitate

A solid that separates from a solution during a chemical reaction.

Characteristic Physical Property

A physical property that is unique to a pure substance and can be used to identify that substance, such as density, melting point, or boiling point.

Density

A measure of how much mass is contained in a given unit volume of a substance, calculated using $\text{density} = \frac{\text{mass}}{\text{volume}}$.

Freezing Point

The temperature at which a substance changes state from a liquid to a solid; it occurs at the exact same temperature as the melting point of that substance.

Melting Point

The temperature at which a substance changes state from a solid to a liquid.

Boiling Point

The temperature at which a substance changes state rapidly from a liquid to a gas.

Element

A pure substance that cannot be broken down into a simpler chemical substance by any physical or chemical means.

Element Symbol

An abbreviation used on the periodic table to represent a chemical element, consisting of one or two letters.

Compound

A pure substance composed of two or more different elements that are chemically joined together.

Metal

An element that is typically lustrous, malleable, ductile, and a good conductor of heat and electricity, located to the left and central parts of the periodic table.

Non-metal

An element that is usually a gas or a dull, powdery solid and does not conduct heat or electricity well, located on the upper right portion of the periodic table.

Metalloid

An element located along the staircase line of the periodic table that possesses both metallic and non-metallic properties.

Chemical Family

A vertical column of elements (group) on the periodic table whose members share similar physical and chemical properties.

Alkali Metal

An element found in Group 1 of the periodic table; characterized by being shiny, silvery, soft, and highly reactive, with reactivity increasing down the column.

Alkaline Earth Metal

An element found in Group 2 of the periodic table; shiny and silvery, but not as soft or as reactive as the alkali metals.

Halogen

An element found in Group 17 of the periodic table; an extremely reactive non-metal whose reactivity increases as you move up the column.

Noble Gas

An element in Group 18 of the periodic table; a colourless, odourless, unreactive gas with a full outermost electron orbit that glows brightly when an electric current passes through it.

Period

A horizontal row of elements on the periodic table showing recurring trends in chemical reactivity and properties.

Atom

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

Electron

A tiny, negatively charged subatomic particle that orbits the nucleus of an atom.

Proton

A positively charged subatomic particle located in the nucleus of an atom.

Neutron

A neutral subatomic particle located in the nucleus of an atom with approximately the same mass as a proton.

Atomic Number

The number of protons found in an atom's nucleus, unique to each element and determining its identity.

Mass Number

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

Isotope

An atom that has the same number of protons as other atoms of that element, but a different number of neutrons.

Atomic Mass

The average mass of an atom of an element measured in atomic mass units ($\text{u}$), representing a weighted average of all its natural isotopes.

Bohr–Rutherford Diagram

A drawing that depicts the numbers and locations of protons and neutrons in the nucleus, along with electrons arranged in concentric orbits around the nucleus.

Molecule

A unit formed when two or more atoms of the same or different elements are chemically joined together.

Chemical Formula

A notation that indicates the type and number of atoms present in a pure substance.

Molecular Element

A molecule consisting of two or more atoms of the same element chemically bonded together.

Diatomic Molecule

A molecule composed of exactly two atoms of the same or different elements; the seven homonuclear elemental examples are $H_2$, $N_2$, $O_2$, $F_2$, $Cl_2$, $Br_2$, and $I_2$.

Molecular Compound

A molecule that consists of two or more different elements chemically bonded together.

Ion

A charged particle formed when an atom loses or gains one or more electrons without changing its number of protons.

Cation

A positively charged ion formed when an atom, typically a metal, loses one or more electrons.

Anion

A negatively charged ion formed when an atom, typically a non-metal, gains one or more electrons.

Ionic Compound

A compound that consists of positively and negatively charged ions held together by an ionic bond.

Covalent Bond

A chemical bond formed when two non-metal atoms share one or more pairs of electrons.

Catalyst

A substance that speeds up a chemical reaction without being consumed or chemically altered itself.