Matter and Materials Glossary
- air valve: a device that works as a gateway to allow air to flow in only one direction (either into or out of something
- atomic nucleus: a tightly packed cluster of protons and neutrons at the centre of the atom
- atoms: the fundamental particles that all matter is made up of
- boiling point: the temperature at which a particular material changes from the liquid to the gas state (boils)
- boiling: occurs within a liquid when it is heated to its boiling point and particles escape as bubbles of gas from the liquid
- chemical bond: a special force that holds the atoms in a molecule together
- chemicalequation: a way of representing a chemical reaction in terms of the chemical formulae of the reactants and products
- chemical formula: a combination of element symbols that shows the types and number of atoms in one molecule of a certain compound
- chemical reaction: a process in which chemical bonds are broken and new ones are formed between atoms; atoms in the starting compounds, called reactants, are rearranged to form new compounds, called products
- chemical reaction: an event during which the atoms in molecules are rearranged to form new molecules
- cluster: (verb) to come together and form a tight group
- coefficients: the numbers in front of the atom and molecule formulae in the chemical equation; they represent the ratio of the numbers of individual molecules that take part in the chemical reaction
- collide: (noun: collision) to bump or crash into something
- compound: a pure substance in which atoms of two or more different chemical elements are bonded in some fixed ratio
- compress: (adjective: compressible) to squeeze the particles of a material closer together
- condensation: when energy is removed and a gas changes state to a liquid
- constant motion: something that is in constant motion never stops moving
- contract: the physical size of an object gets smaller
- controlled experiment: an experiment in which the variables are controlled so that the results can be compared to those obtained in another experiment
- decomposition reaction: a chemical reaction in which a given molecule is broken up and recombined into smaller molecules
- density: the mass of a substance in a given space (volume)
- diffuse: (noun: diffusion) the movement of particles so that they end up spread out randomly and uniformly in a given space
- disordered: untidy; without regular arrangement
- distinction: the separation of things into different groups according to features or characteristics
- electrons: the smallest of the three types of sub-atomic particles; they are negatively charged and are located outside the atomic nucleus
- element: a pure substance made up only of atoms of the same kind
- energetic: full of energy
- evaporation: when energy is added and the particles at the surface of a liquid change state to a gas
- expand: the physical size of an object gets bigger
- fermentation: a chemical reaction that occurs in the presence of yeast and/or bacteria, during which a sugar is converted to an alcohol or an acid
- forces of attraction: forces that particles experience which draw them closer to each other
- immiscible: incapable of mixing or blending
- impact: (noun) effect
- mass: a measure of the amount of matter in an object or material
- melting point: the temperature beyond which a particular material changes from the solid to the liquid state (melts)
- melting: when energy is added and a solid changes state to a liquid
- mixture: a combination of two or more pure substances mixed together
- molecule: two or more atoms that have chemically bonded with each other; the atoms in a molecule can be of the same kind (in which case it would be a molecule of an element), or they can be of different kinds (in which case it would be a molecule of a compound)
- neutrons: a type of sub-atomic particle similar to protons in mass and size, but neutral (without charge); neutrons together with protons make up the atomic nucleus
- observation: an observation is something we can see, hear, taste, smell or feel
- phenomenon: (plural: phenomena) an event or occurrence that we can observe with our senses
- physicalquantity: something that can be measured or estimated
- postulate: a claim that can be supported by experimental evidence
- pressure gauge: an instrument used to measure the gas pressure inside something
- product: a substance that forms during the reaction; it will be present after the reaction has taken place
- protons: a type of sub-atomic particle that is positively charged and occurs inside the atomic nucleus along with neutrons
- pure substance: matter that consists of the same material throughout; two classes exist, namely elements and compounds
- random: unpredictable
- rate: how fast or slow an event (e.g. diffusion) occurs
- reactant: a substance that is present before the reaction takes place; it is a starting material of the reaction
- reaction flask or reaction vessel: the container in which the reaction has taken place; small scale chemical reactions done in a laboratory are usually performed in glass beakers or flasks
- regular arrangement: an arrangement of particles in a neatly packed, consistent and repetitive pattern
- reinforce: to make stronger, usually by the addition of another material or other form of support
- reverse: in this chapter reverse means 'opposite', as in: melting and freezing are reverse processes (the opposite of each other)
- scientific model: a set of ideas that represents a concept, object, or process in nature to help us understand it
- scientific theory: an explanation of scientific phenomena or aspects of the natural world, supported and confirmed by facts obtained through observation and experimentation
- solidifying: (freezing) when energy is removed and a liquid changes state to a solid
- sub-atomic particle: a particle that is smaller than the atom and occurs inside the atom
- transformation: change; to transform is to change from one form into another
- uniform: the same throughout
- vapour: the gaseous state of a substance that is normally liquid or solid at room temperature, such as water that has evaporated into the air
- vibrate: to move rapidly back and forth
- vigorous: strong and forceful
- volume: a measure of the amount of space occupied by a three-dimensional object or material