Basic Science Vocabulary

Science is the systematic study of the natural world. Here are some of the words and their scientific meanings that you will probably come across as you study science.

The words are listed in alphabetical order. Any word in bold is one of the words in the list.

atom – the smallest unit of a chemical element

cell – the smallest unit of living matter

charge – the amount of electricity carried by an object (a charge can be positive or negative – if two objects each have a positive charge or a negative charge, they are attracted to each other – if one object has a positive charge and the other a negative charge, they repel one another)

clone – an organism that is genetically identical to the unit or individual from which it was derived

compound – a substance that is composed of two or more elements

conductor – any material through which electricity and heat flow easily (opposite of insulator)

electron – a tiny particle that has a negative charge and orbits the nucleus of an atom

element – a substance that cannot be broken up into a simpler substance (118 elements have been identified at this time)

gas – a state of matter that has no definite shape or volume, such as air

homeostasis – the tendency of a system to maintain internal stability

insulator – any material through which electricity or heat does not flow easily (opposite of conductor)

ion – an atom or molecule that has an electric charge

liquid – a state of matter that has definite volume but no definite shape, such as water

matter – something that has mass and can exist as a solid, liquid, or gas

molecule – two or more elements that are chemically joined

nucleus – the central part of an atom

organism – any living thing able to carry out life on its own

proton – a positively charged particle located in the nucleus of an atom

radiation – the movement of heat from one place to another by waves or particles

resistance – the extent to which a material opposes the flow of electricity (copper is used in electrical wiring because copper has low resistance)

solid – a state of matter that has both definite shape and volume, such as ice

solvent – a substance, usually a liquid, that can dissolve another substance

stimulus – anything in the environment that causes a living thing to react

substance – anything that has mass and occupies space

symbiosis – a close and prolonged association between two or more different organisms of different species (there is usually some benefit to each organism)

tropism – the response of a plant toward or away from a stimulus

velocity – the speed and direction of an object’s motion

These are just some of the words whose meanings you will need to know when you study science. There will be many others. It is a good idea to write the science words and their meanings you encounter throughout school in a science notebook.