As part of her nuclear stress test, simone starts to walk on the treadmill. when she reaches the maximum level, paul injects a radioactive dye with201tl with an activity of 72 mbq . the radiation emitted from areas of her heart is detected by a scanner and produces images of her heart muscle. after simone rests for 3 h, paul injects more dye with 201tl and she is placed under the scanner again. a second set of images of her heart muscle at rest is taken. when simone's doctor reviews her scans, he assures her that she had normal blood flow to her heart muscle, both at rest and under stress.
part a
if the half-life of 201tl is 3.0 days, what is its activity, in megabecquerels after 3.0 days?
express the activity to two significant figures and include the appropriate units.
part b
what is its activity in megabecquerels after 6.0 days?
express the activity to two significant figures and include the appropriate units.

At room temperature what happens to the average kinetic energy of the molecules of a solid, liquid, and a gas

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.

22. a flask containing 450 ml of 0.50 m h2so4 was accidentally knocked to the floor. how many grams of nahco, do you need to put on the spill to neutralize the acid according to the following equation: h2so4(aq)+2 nahcos(aq) na,so(aq) +2 h20()+2 co2(g) d) 38 g a) 2.3 g b) 9.5 g c) 19 g