Carbon-14 undergoes a beta (b) decay with a half-life of 5730 years. a sample of carbon dioxide isolated from the atmosphere was observed to have 13.6 disintegrations per minute. however, a sample of atmospheric methane (containing the same number of carbon atoms) was observed to have 11.1 disintegrations per minute (assume that all of the carbon in the carbon dioxide sample is "fresh" carbon. "fresh'" meaning that the amount of 14c atoms in the sample has not fallen from the steady-state value for all living things in the environment) why is there a lower rate of beta decay in the methane sample? a. b. a similar sample of methane was isolated from a section of permafrost in the canadian tundra and found to have 3.1 disintegrations per minute. how long ago did that section freeze? 0.693 hint: recall that half-life, l/- -and k is the rate constant for the decay. 1/ 2 also remember that the general form of exponential decay is n- n, exp-kt) where n is the amount of "c at any given time (t) no is the original amount of 4c

Which term refers to a property that depends only on the amount of a substance? ©@

Nconcentration refers to the molar concentration of an ion in solution. it may be identical to, or greater or less than, the molar concentration of the compound containing the ion that was used to make the solution. for soluble salts, the molarity of a particular ion is equal to the molarity of that compound times the subscript for that ion. for example, 1 m of alcl3 is 1 m in al3+ and 3 m in cl−. 1 m of (nh4)2so4 is 2 m in nh4+ and 1 m in so42−. part a what is the concentration of k+ in 0.15 m of k2s? view available hint(s) nothing m m part b if cacl2 is dissolved in water, what can be said about the concentration of the ca2+ ion? view available hint(s) if is dissolved in water, what can be said about the concentration of the ion? it has the same concentration as the cl− ion. its concentration is half that of the cl− ion. its concentration is twice that of the cl− ion. its concentration is one-third that of the cl− ion. part c a scientist wants to make a solution of tribasic sodium phosphate, na3po4, for a laboratory experiment. how many grams of na3po4 will be needed to produce 550 ml of a solution that has a concentration of na+ ions of 0.700 m ? express your answer numerically in grams. view available hint(s) mass of na3po4 n a 3 p o 4 = nothing g provide feedback

What is happening when the water inside a kettle heats up and begins to boil