Matter (SCI)

• Matter takes up space and has mass. Matter is made up of atoms.
• Matter can be classified into different states : solid, liquid, gas
• Matter's fourth state is plasma
• Liquid matter has fixed volume but changes its shape according to the container that holds it. When pressure is applied to it, it flows.
• plasma is electrically charged gas and plasma particles are are electrically charged
• Gas matter has no definite shape or volume. Gas molecules move freely and collide with one another and their surroundings. They take on the shape of their container.
• The physical properties of matter include density, hardness, melting point, boiling point, conductivity, solubility, viscosity, refractive index, surface tension, cohesion, adhesion, ductility, malleability, thermal expansion coefficient, electrical conductivity, magnetic permeability, specific heat capacity, compressibility, elasticity, and optical properties such as color, transparency, opacity, reflectance, and refraction.
• Solid matter has a definite shape and volume. The particles in solids vibrate around fixed positions.
• Melting point is the temperature at which a solid substance turns into a liquid.
• Conductivity refers to the ability of a material to transmit electricity or heat.
• Boiling point is the temperature at which a liquid substance turns into a gas.
• A substance has a definite chemical composition and can be classified as an element or compound
• An element has only one type of atom and therefore cannot be broken down through chemical means
• Compounds are made up of two or more elements that have been chemically combined together
• Mixtures are made of pure substances
• A homogenous mixture is uniform
• A heterogeneous mixture contains different components that do not mix evenly
• Liquid have no fixed shape but take on the shape of their container, medium density, medium compressibility and medium melting points
• Chemical reactions involve the breaking and forming of bonds between atoms to form new compounds.
• Combustion is a reaction where oxygen reacts with another substance to produce carbon dioxide and water vapour
• Gases have no definite volume or shape, low density, high compressibility and very low melting point