Define and discuss heterogeneous mixtures. Determine main characteristics. Discuss both main types of heterogeneous mixtures, suspensions and colloids with regard to particle size. Identify some typical suspensions used in chemistry and medicine. Define a Thixotropic mixture and use examples such as paint, toothpaste and types of clay.
Review definition of pure substance. Elicit a definition of a mixture including the definition of a pure substance. Determine that substances can be separated by physical means, and discuss mixtures of iron and sulfur along with mercury and silver. Arrive at a definition for a homogenous mixture, and review solute and solvent terms, miscible and miscible, and soluble and insoluble. List and discuss the 6 major types of homogenous mixtures.
Determine by observation what occurs when a solid piece of ice is slowly heated. List and discuss the 3 major states of matter, and add the plasma state. For each state, discuss the properties and characteristics. Include: shape and volume, particle arrangement, expansion when heated, taking container shape, compressibility, hardness. Define difference from a gas and a vapor.
List the phases as states of matter and define and discuss the main characteristic and properties of each state. Discuss shape and volume, molecular packing, expansion when heated, adjustment to container, compression, and hardness of samples. Discuss how for solid ice the density decreases from the liquid phase, all other substances the density will increase. View and discuss image sheets for each phase.
Determine a definition for matter based on mass measurement and volume occupied by that mass. Define a substance and extend the definition to define a pure substance. Relate uniform and unchanging composition. Use a mix of iron filings and sulfur powder as a mix of two pure substances and define them as a mixture. Note that each retains its own individual properties, e.g. magnetism for iron. Determine that substances can be separated by physical means. Use example of silver and mercury used in tooth filings. They can be separated by temperature of evaporation.
Elicit a definition of matter based on the properties of mass and volume. Discuss how air is also classed as matter, and work out a lab which can be used to determine the mass and volume of a given amount of air. Use table salt as an example of matter, determine its formula and then discuss how table salt is classed as a pure substance. Determine that water is also a pure substance, but sea water is not. Explain the difference. Outline that chemistry will focus on the composition of substances and how they interact.
