_____________________________________________________________________CHEM 100 LECTURE UNIT 1. FOUNDATIONS OF CHEMSITRY Chemistry is the study of matter and the changes it undergoes. Matter is anything that occupies space and has mass. Applications of Chemistry • Energy and the Environment • Fossil fuels • Solar energy • Nuclear energy Health and Medicine • Sanitation systems • Surgery with anesthesia • Vaccines and antibiotics Materials and Technology • Polymers, ceramics, liquid crystals • Room-temperature superconductors? • Molecular computing? Food and Agriculture • Genetically modified crops • “Natural” pesticides • Specialized fertilizers
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Classification of Matter
A substance is a form of matter that has a definite composition and distinct properties. An element is a substance that is composed of tiny particles called atoms. A compound is a substance composed of atoms of two or more elements chemically united in fixed proportions. Compounds can only be separated into their pure components (elements) by chemical means. A mixture is a combination of two or more substances in which the substances retain their distinct identities. Physical means can be used to separate a mixture into its pure components. Homogenous mixture – composition of the mixture is the same throughout. Heterogeneous mixture – composition is not uniform throughout.
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_____________________________________________________________________CHEM 100 LECTURE PROPERTIES OF MATTER Physical properties: readily observable/measurable without altering the composition or identity of a substance. (mass, color, density, boiling point) Chemical properties: can only be observed by altering the composition or identity of the substance(s) involved. (combustibility, flammability, oxidizability) An extensive property of a material depends upon how much matter is being
