The main reason that it's important to test only one variable at a time is so that a. qualitative data can be recorded. b. scientists can easily tell which variable caused the results. c. scientists can have many hypotheses tested at once. d. quantitative data can be recorded.

In order to calculate the amount of heat transferred you must know the __ and specific heat of the material, as well as the change in temperature. a. volume b. density c. mass d. enthalpy

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.

Draw the lewis structure for the trisulfur s3 molecule. be sure to include all resonance structures that satisfy the octet rule.