Radioactivity

After 548 hours decreases the activity of a radioactive substance to 1/9 of the initial value. What is the half-life of the substance?

Correct answer:

t1/2 =  172.9 hours

Step-by-step explanation:

(12)548t1/2=19  t1/2=548ln(0.5)ln(1/9)=172.9 hours



Did you find an error or inaccuracy? Feel free to write us. Thank you!



avatar







Tips to related online calculators
Do you want to convert time units like minutes to seconds?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions:

  • The half life
    exp_growth2 The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 145 grams of a radioactive isotope, how much will be left after 3 half-lives?
  • Suppose 2
    exponentialFexsDecay Suppose that the half-life of a substance is 250 years. If there were initially 100 g of the substance, a. Give an exponential model for the situation b. How much will remain after 500 years?
  • Half life
    Bi Determine the half life of bismuth, when bismuth weight from the original weight of 32 g was only 2 grams in 242 minutes.
  • Exponential equation
    exp Find x, if 625 ^ x = 5 The equation is exponential because the unknown is in the exponential power of 625
  • Two numbers
    maxwells-equation We have two numbers. Their sum is 140. One-fifth of the first number is equal to half the second number. Determine those unknown numbers.
  • Radioactive material
    radium A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?
  • Crystal
    crystal The crystal grows every month 1.2 permille of its mass. For how many months to grow a crystal from weight 177 g to 384 g?
  • Exponential equation
    exp Determine the value of having y in the expression (3^y): (4^-1)=36. Unknown y is a natural number greater than zero.
  • Lifespan
    normal_d The lifetime of a light bulb is a random variable with a normal distribution of x = 300 hours, σ = 35 hours. a) What is the probability that a randomly selected light bulb will have a lifespan of more than 320 hours? b) Up to what value of L hours can the
  • Deceleration of car
    cars The car has a speed of 60 km/h and after 100 m journey speed of 40 km/h. What is the deceleration of a car if we assume that its movement is constantly slowed down?
  • Car value
    car_old The car loses value 15% every year. Determine a time (in years) when its price will halve.
  • Exponential warm
    teplomer Suppose that a body with temperature T1 is placed in surroundings with temperature T0 different from that of T1. The body will either cool or warm to temperature T(t) after time t, in minutes, where T(t)=T0 + (T1-T0)e^(-kt) . If jello salad with 30 degree
  • In the
    covid19 In the workshop, it was necessary to quickly complete the production of veils for the hospital. The workshop staff promised to work an additional 240 hours to produce this order in March. The workshop has eight employees who work 160 hours a month. What p
  • Exponential equation
    exp Solve exponential equation (in real numbers): 98x-2=9
  • What is 9
    mixed_fractions What is the value of x in the proportion 2 and one-fourth over x = 1 and one-half over 3 and three-fifths? 2 and two-fifths 5 and two-fifths 8 and 1 over 10 12 and 3 over 20
  • Enterprise
    podniky_socik The value of annual production enterprise is 7.1 million USD. The average annual growth rate is 1.5%. What will be value of production at the end of the fifth year?
  • Tachometer
    tatra-dakar2 Tatra's tachometer shows the initial state 886123 km this morning. Tatra today travels at an average speed of 44 km/h. Determine the function that describes the Tatra's tachometer depending on the time. What is the state of the tachometer after 4 hours?