PLEASE HELP!!! Refer to the observations of the test tubes from part A. Determine which metal (or hydrogen) in each test tube is more reactive. Remember that the less reactive metal (or hydrogen) will typically end up in pure form as an element, so no reaction will occur if the less reactive metal (or hydrogen) is the one that begins in pure form.

Which of the following elements is a representative element? a. chromium (cr) b. aluminum (al) c. mercury (hg) d. silver (ag)

Abullet found at a crime scene may be used as evidence in a trial if the percentage of metals match to the composition of metals in a bullet from the suspect's ammunition. a forensic scientist's analysis of the bullet shows that it contains 11.9 g of lead, 0.5 g of tin, and 0.8 b of antimony. what is the percentage of lead metal in the bullet? express your answers to the one's place.

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?