1. Describe el elemento asignado: a. nombre, b. símbolo c. #atómico, d. masa atómica, e. dónde se encuentra y cuáles son sus usos, f. p+, e-,n0, g. grupo y periodo, h. quién lo descubrió, año,
dónde, i. clasificación en la tabla periódica, j. estado en que se encuentra(sólido, líquido, gas),
k. punto de fusión I. punto de ebullición *

Achemical reaction (also known as a chemical change) produces substances that are chemically different from the starting materials. an example of a chemical reaction is the formation of water from hydrogen and oxygen gas. in a physical change, a substance changes its physical appearance but not its chemical identity. an example of physical change is the formation of liquid water from solid water, a familiar process called melting. physically, liquid water looks very different from solid water (ice) but the chemical identity, water, is the same for both. which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? oxygen gas changes to ozone during thunderstorms carbon dioxide is produced by the combustion of gasoline in an automobile engine. when coal, oil, and natural gas are decomposed in landsills they produce methane gas. freezing rain develops when a warm air mass overrides a cold air mass. fog forms from water vapor when the temperature drops below the dew point

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.