What is Matter? Matter = anything that takes up space and has mass Matter is either a substance or a mixture Substance - all particles in matter are identical (fixed composition) Mixture – two or more substances physically combined (variable composition)

Two Types of Substances Element: simplest form of matter from which more complex substances are made (listed on the Periodic Table) all the atoms that make up an element are alike Ex. Helium Balloons are filled with the element Helium, thus the balloons pictured.

Elements – a molecular look Elements can exist like: Helium, Argon, and Neon that are stable as an individual atom Oxygen, Nitrogen and Hydrogen that are stable as two atoms of themselves bonded together (O2, N2, H2)

Two Types of Substances Ex. NaCl (Table Salt) Compound: two or more elements chemically combined in a fixed proportion Can be broken down, but only by chemical reactions Have properties different than the elements that make them up Ex. H2O (Water) Ex. C6H12O6 (Sugar)

Substances – a molecular look The difference between an element and a compound: Element: just 1 substance; the simplest form Ex. Oxygen (O2) Compound: 2 or more elements chemically combined Ex. Carbon dioxide (CO2)

Two Types of Mixtures Homogeneous: components are evenly distributed out on a microscopic level Solutions (when one substance is dissolved into another) are homogeneous mixtures Usually appears “blended” Ex. Bleach, Lemonade, Blood, Coffee Make sure they know solutions don’t always have to be a solid (solute) dissolved in a liquid (solvent) Ex. Air, alloys like bronze, etc.

Two Types of Mixtures Heterogeneous: substances in the mixture are not evenly spread out Different components are easy to see, or separate out over time Ex. Salad dressing, paint, cereal, peanut butter

Mixtures – a molecular look The difference between a homogeneous vs. a heterogeneous mixture: Homogeneous: even distribution; “same” Ex. Salt water Heterogeneous: uneven distribution; “different” Ex. Salad dressing

Classifying Matter Flow Chart Fixed proportion Physically combined On the PT Chemically combined Different Same