Classification of Matter

Matter Matter: Anything that has mass and volume 3 phases of matter

The Nature of Matter Gold Mercury Chemists are interested in the nature of matter and how this is related to its atoms and molecules.

Chemistry & Matter We can explore the MACROSCOPIC world — what we can see — to understand the PARTICULATE worlds we cannot see. We write SYMBOLS to describe these worlds.

A Chemist’s View of Water Macroscopic H2O (gas, liquid, solid) Symbolic Particulate

A Chemist’s View Macroscopic 2 H2(g) + O2 (g) --> 2 H2O(g) Particulate Symbolic

Kinetic Nature of Matter Matter consists of atoms and molecules in motion.

STATES OF MATTER Solids — have rigid shape, fixed volume. External shape can reflect the atomic and molecular arrangement. Liquids — have no fixed shape and may not fill a container completely. Gases — expand to fill their container.

OTHER STATES OF MATTER PLASMA — an electrically charged gas; Example: the sun or any other star BOSE-EINSTEIN CONDENSATE — a condensate that forms near absolute zero that has superconductive properties; Example: supercooled Rb gas

Physical Properties Characteristic of a substance that can be observed (using your senses) without changing the substance into something else. Physical properties are used to identify, describe and classify matter. Hardness Texture Color Odor Taste Temperature

More EXAMPLES - Physical size, shape, freezing point, boiling point, melting point, magnetism, viscosity, density, luster and many more. Viscosity - The resistance of a liquid to flowing. Examples: Low viscosity-water, rubbing alcohol High viscosity-honey

Physical Changes can be observed without changing the identity of the substance Some physical changes would be boiling of a liquid melting of a solid dissolving a solid in a liquid to give a homogeneous mixture — a SOLUTION.

Creating a new chemical product Chemical Properties Chemical properties are characteristics involved when a substance interacts with another substance to change its chemical make-up. Flammability Rusting Creating gas bubbles Creating a new chemical product Reactivity with water pH

Chemical Change Burning hydrogen (H2) in oxygen (O2) gives H2O. Chemical change or chemical reaction — transformation of one or more atoms or molecules into one or more different molecules.

Classification of Matter Now that we have defined chemical and physical properties of matter, we can use that to help us classify it. One way chemists classify matter is based on its purity.

Heterogeneous Mixture Matter Can be separated physically Cannot be separated physically Mixture Pure Substance Cannot see the parts Can be separated chemically Can see the parts Cannot be separated Heterogeneous Mixture Homogeneous Mixture Compound Element suspension colloid Most impure Most pure

Suspension Heterogenous mixture containing solid particles that are sufficiently large for sedimentation (or settling). Example: sand in water

Colloid A colloid is a substance microscopically dispersed throughout another substance. Dispersed particles are very small and have a diameter of between approximately 2 and 500 nanometers. Example: homogenized milk

Classification of Matter Pure Substance – Matter that has only 1 set of chemical and physical properties. Example: Pure water always has the exact same chemical and physical properties under the same conditions. If water ever tastes different then it isn’t pure water; it fits into our next category.

Classification of Matter Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties. Example: Copper and Zinc can be mixed together to produce brass. Even though it may look different, it is still copper and zinc. Each metal retains its own properties like melting point.

Classification of Matter Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties. Unlike pure substances, mixtures can always be separated by physical means. How could we separate the copper and zinc back out?

Mixtures Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties. If a sample of sand contains iron and salt, how could you separate them from the other minerals?

Pure Substances Pure substances can also be divided into 2 categories: compounds and elements.

Pure Substances Compound – Two or more elements chemically bonded together. Examples: Carbon Dioxide (CO2) Water (H2O) Salt (NaCl) Sucrose (C12H22O11)

Pure Substances Compounds have only 1 set of properties. They cannot be separated by any physical process. - Can only be separated by a chemical reaction. Water can be separated into Hydrogen and Oxygen by a process called Electrolysis.

Pure Substances Elements – Substances made up of only one type of atom. - Cannot be separated by any physical OR chemical process. Examples: Carbon Helium Gold

Classify the following slide using these five classifications: - Non-matter - Heterogeneous Mixture - Homogeneous Mixture - Compound - Element

Helium He Diamond C Electricity Bronze Cu + Sn Italian Dressing Heat Light Steel Fe + C Air N2 + O2 + Ar + CO2 Mercury Hg Cookie Salt Water H2O + NaCl Water H2O Iron Fe Carbon Dioxide CO2

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