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

Astudent made a graph plotting the progress of a reaction over time. the student forgot to label the y-axis of the graph. a graph is shown with two graph lines. one graph line starts at a higher position on the y axis and slopes downwards towards the right. the other graph line starts at a lower position on the y axis and slopes upwards towards the right. the two graph lines stop short of intersecting each other and continue as separate lines which gradually become straight and parallel to the x axis. a vertical line is shown at a point where the two graph lines finally became parallel to the x axis. this vertical line is labeled equilibrium. the title on the x axis is time and an arrow pointing towards the right is shown above time. the title on the y axis is left blank. what best explains the label that the student should use on the y-axis? amount, because as the amount of product decreases, the amount of reactant increases over time. reaction rate, because forward and backward reaction become equal at equilibrium. amount, because the amounts of reactants and products become constant after equilibrium is reached. reaction rate, as the rate of forward reaction increases and rate of backward reaction decreases over time.

Which of the following best describes technology a. something created for only scientists to use b.the method of thinking that scientists use. c.the application of engineering to create useful products. c. a scientific idea

To calculate the molarity of a solution, you need to know the moles of solute and the