CHEM 1101 Chapter Notes - Chapter 1: Decimal Mark, Significant Figures, Chemical Compound
14 Dec 2016
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Pure substance- uniform in chemical composition and properties: two groups. Chemical compound: yield a simpler substance when broken down. Elements: cannot yield a simpler substance or be broken down. Mixture- can vary both in composition and properties. Homogenous- blend of 2+ pure substances having uniform composition. Heterogeneous- blend of 2+ pure substances having non-uniform composition. Doesn"t easily dissolve: components can be separated without changing their chem. identities. Metals: solid at room temp, good conductors, malleable, lustrous. Nonmetals: poor conductors, brittle, gasses, or liquid. Metalloids: properties intermediate between those or metals and nonmetals. Significant digits- total number of digits used to express such a measurement: 94. 072 5 sig figs. Zeroes in the middle of a number are significant: 2. Zeroes at the beginning of a number are not significant: 3. Zeroes at the end of a number after a decimal point are significant: 4.
