Trex is a manufactured substitute for wood compounded from post-consumer plastic and wood. it is frequently used in outdoor decks. its density is reported as 60.0 lb/f t 3 . what is the density of trex in kg/l ?

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.

Examples of states of consciousness include a. daydreaming b. dreaming during sleep c. hypnosis d. all of the above

The radioactive isotope of lead, pb-209, decays at a rate proportional to the amount present at time t and has a half-life of 3.3 hours. if 1 gram of this isotope is present initially, how long will it take for 80% of the lead to decay? (round your answer to two decimal places.)