Elements and Compounds Vocabulary

Define: atom.

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

• A molecule made up of two or more elements.

• A substance that cannot be broken down into simpler substances.

• A particle that carries a positive charge.

Define: atomic number.

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

• The number of neutrons in the nucleus of an atom.

• The total number of electrons in an atom.

• The sum of protons and neutrons in the nucleus of an atom.

Define: boiling point.

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

• The temperature at which a solid changes to a liquid.

• The temperature at which a gas changes to a solid.

• The temperature at which a substance freezes.

Define: brittle.

• A property of a material that causes it to break or shatter easily under stress.

• A property of a material that allows it to stretch without breaking.

• A property of a material that allows it to conduct electricity.

• A property of a material that resists corrosion.

Define: chemical bond.

• A force that holds two or more atoms together in a molecule or compound.

• A type of chemical reaction that releases energy.

• A process by which atoms lose electrons.

• A measurement of the mass of an atom.

Define: chemical formula.

• A representation of a substance using symbols for its constituent elements.

• A list of all physical properties of a substance.

• A method for separating mixtures into elements.

• A process for measuring the mass of a compound.

Define: chemical reaction.

• A process in which substances interact to form new substances with different properties.

• A process in which substances are physically mixed without any change in their properties.

• A process in which energy is only absorbed but no new substances are formed.

• A process in which substances are separated into their original components without any change.

Define: chemical symbol.

• A one- or two-letter abbreviation for a chemical element.

• A type of chemical reaction.

• A laboratory safety symbol.

• A unit of measurement for mass.

Define: compound.

• A substance made up of two or more different elements that are chemically bonded together.

• A mixture of two or more substances that are not chemically bonded.

• A single element in its purest form.

• A physical change in the state of matter.

What is the temperature at which a substance changes from liquid to gas called?

• Boiling point

• Freezing point

• Melting point

• Condensation point