a fossil is any natural evidence of prehistoric life that provides some idea of the size, shape, or form of the organism. a fossil does need not to be a whole animal or plant. broken fragments are also fossils, as are the tracks left behind by the organisms. fossils provide important evidence of how life and environmental conditions have changed. the fossils found in rock formations of different time periods differ because the environment on earth has changed.
position of land masses of early pennsylvania can be determined through fossil records because we know that most plants presently live on land. from this information, we can infer?

Consider three unlabeled bottles, each contain small pieces of one of the following metals. - magnesium - sodium - silver the following reagents are used for identifying the metals. - pure water - a solution of 1.0 molar hcl - a solution of concentrated hno3 (a) which metal can be easily identified because it is much softer than the other two? describe a chemical test that distinguishes this metal from the other two, using only one of the reagents above. write a balanced chemical equation for the reaction that occurs. (b) one of the other two metals reacts readily with the hcl solution. identify the metal and write the balanced chemical equation for the reaction that occurs when this metal is added to the hcl solution. use the table of standard reduction potentials (attached) to account for the fact that this metal reacts with hcl while the other does not. (c) the one remaining metal reacts with the concentrated hno3 solution. write a balanced chemical equation for the reaction that occurs. (d) the solution obtained in (c) is diluted and a few drops of 1 m hcl is added. describe what would be observed. write a balanced chemical equation for the reaction that occurs.

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel

Apound is approximately 0.45 kilogram. a persons weighs 87 kilograms. what is the persons’s weight, in pounds, when expressed to the correct number of significant figures