# Properties of Elements: Essay

907 Words4 Pages
Properties of Elements: Property: A way to describe matter (stuff) Intensive Properties: Do not depend on how much. (color) Extensive Properties: Do depend on how much. (mass, height, volume, length, count) Physical Properties: That have to do with nature of a matter. (what color, ect) Chemical Properties: Reactions!! A+B=C Alkali Metals: 1A Li, Na, K (very shinny metals) ( reacts strongly with water) Alkaline Earth Metals: A2 Mg, Ca Halogen: 7A gasses Nobel gases: 8A glowing, signs ect. (non reaction) Most elements are metals: shinny, conduct electricity, ductile, high melting points. Non metals: more brittle, dull, most non metals are gases. And non conductors, insulators, and have a low melting and freezing point. Semimetals: Si some properties are metal some are not. Derived Units: Quantity Definition Derived Unit (Names) Area Length times length m2 Volume Area times length m3 Density Mass per unit volume kg/m3 or g/cm3 Speed Distance per unit time m/s Acceleration Change in speed per unit time m/s2 Force Mass times acceleration (kg*m)/s2 Pressure Force per unit area kg/ (m*s2) Energy Force times Distance (kg*m2)/s2 ¬¬___g___ = mass = stuff 1cm3 volume space Question 1: A metal sample is hammered into a rectangular sheet with an area of 3.2 ft2 and an average thickness of 2.30 X 10-6 cm. If the mass of this sample is 0.4767 g, predict the identity of the metal. (1in = 2.54 cm). (1 ft= 12 inches) (1in = 2.54 cm) A. Aluminum (2.30 g/cm3) B. Copper (8.95 g/cm3) C. Gold (19.3 g/cm3) D. Zinc (7.15 g/cm3) Accuracy and Precision: Precision is the ability to repeat a measurement. Significant Figures 0 1 2 3 4 Between 1.7 and 1.8 = 1.75 < has three significant figures Rounding Numbers: Rules of counting significant figures (left to