Properties of Substances and Atomic Theory - Vocabulary Flashcards

Vocabulary flashcards covering key terms and definitions from the lecture notes.

Characteristics that can be observed or measured without changing the substance.

Physical properties

How a substance reacts to form new substances.

Chemical properties

A change in appearance or state without changing the substance's identity.

Physical change

A process that results in the formation of new substances with different properties.

Chemical change

A chart of elements arranged by increasing atomic number and recurring properties, created by Dmitri Mendeleyev.

Periodic Table

Horizontal rows in the periodic table.

Periods

Vertical columns (groups) in the periodic table.

Families

Elements in the A groups; the representative elements.

Main Group Elements

Elements in the B groups; the transition metals.

Transition Elements

The bottom rows (lanthanides and actinides) of the periodic table.

Inner Transition Elements

Energy

The capacity to do work or transfer heat.

Kinetic energy

Energy in motion.

Potential energy

Energy stored due to position.

Law of Conservation of Energy

Energy cannot be created or destroyed; it can be transformed.

Specific heat

The amount of heat required to raise the temperature of a substance by a given amount.

Atom

The basic unit of a chemical element; the smallest unit retaining the element's properties.

Element

A pure substance consisting of only one type of atom.

Compound

A substance formed from two or more elements chemically bonded in fixed proportions.

Mixture

A combination of two or more pure substances that retain their own properties.

Dalton's atomic theory

All matter is made up of very tiny particles called atoms.

Law of Conservation of Mass

Matter cannot be created or destroyed in a chemical reaction.

Law of Constant Composition

A compound contains the same elements in the same proportions by mass.

Monatomic elements

Elements that exist as single atoms under standard conditions.

Diatomic elements

Elements that naturally form molecules of two atoms (e.g., H2, O2, N2, F2, Cl2, Br2, I2).

Polyatomic elements

Elements that exist as molecules containing more than two atoms (e.g., P4, S8).

Proton

Positively charged subatomic particle in the nucleus.

Electron

Negatively charged subatomic particle orbiting the nucleus.

Neutron

Electrically neutral subatomic particle in the nucleus.

Mass number

Total number of protons and neutrons in the nucleus.

Atomic number

Number of protons in the nucleus; defines the identity of the element.

Isotopes

Atoms of the same element with different numbers of neutrons.

Atomic weight

Weighted average of the masses of an element's isotopes.

Metals

Typically solid at room temperature; good conductors and malleable.

Nonmetals

Elements that lack metallic properties; generally poor conductors.

Metalloids

Elements with properties between metals and nonmetals.

Halogens

Group 17 (7A) elements; highly reactive nonmetals.

Alkali metals

Group 1A metals; highly reactive; exclude hydrogen.

Noble gases

Group 8A elements; highly unreactive under standard conditions.

Electron configuration

Description of the arrangement of electrons in orbitals around the nucleus.

Chlorine

Greenish-yellow gas with a sharp, suffocating odor at room temperature.

Water

Colorless, odorless liquid with melting point 0°C and boiling point 100°C.

Sugar (sucrose)

White, odorless solid at room temperature.

Acetic acid

Colorless liquid with a vinegar-like odor; mp about 16.7°C and bp about 118°C.

Nitrogen dioxide

Reddish-brown gas with a sharp, acrid odor.

Oxygen

Colorless, odorless gas essential for most life.

Reactant

A substance that participates in a chemical reaction.

Product

A substance formed as a result of a chemical reaction.