Classification of Matter
Matter is anything that has mass and takes up volume We call that DENSITY Density =
How can matter be classified? Matter can be divided into two categories – cannot be physically separated – can be physically separated
Pure Substances can be divided into two categories Elements – cannot be chemically separated (made up of one kind of atom) – can be chemically separated (made up of two or more elements)
Examples Elements – C, H, O, N, P, S Compounds – NaCl, H2O, CO2, C6H1206
Compounds form to allow elements to become more stable Example: Na is flammable around H2O, and Cl is a toxic gas. When they form a compound together, it is neither flammable nor toxic Compounds form depending on the number valence electrons of 2 or more elements – need 8 valence electrons to be stable Example: Na has 1 valence electron and Cl has 7 valence electrons. They form a compound together called salt.
Mixtures can be divided into two categories – all the parts are evenly distributed (not visible) – all the parts are unevenly distributed (visible)
Examples Mixtures – tea, water, coke Heterogeneous Mixtures – pizza, trail mix
Homogeneous Mixtures are commonly known as solutions Parts of a Solution Solution = Solute + Solvent - “stuff” being dissolved - “stuff” doing the dissolving Example: Salt water Salt = solute Water = solvent
Types of Solution – concentration of solvent is greater than concentration of solute Hypertonic – [ ] of solute is greater than [ ] of solvent – [ ] of both solvent and solute is equal
Methods in Separating Mixtures – separates an insoluble solid from a liquid – separates a soluble solid from a liquid Magnetism – separates solid substances, one of which is magnetic – separates substances based on their density – more dense on the bottom, less dense on the top By Hand – separates substance by hand picking them out
Filtration
Evaporation
Magnet
Floating
By Hand
Pure Substance or Mixture? Helium Kool-Aid Milk Salt Copper Ketchup Pure Substance (Element) Mixture Pure Substance (Compound)