Half-life of a radioactive element
If the half-life of a radioactive element is 30.0 years, how long will it take for a sample to decay to the point where its activity is 70.0% of the original value?
a. 15.4 years
b. 86.1 years
c. 5.0 years
d. 30.8 years
e. 12.2 years
Now Priced at $20 (50% Discount)
Recommended (97%)
Rated (4.9/5)
A scanning electron microscope operating at an accelerating voltage of 10 kV accelerates electrons to 20% of the speed of light, calculate the wavelength of the electron.
At 298 K a cell reaction has a standard emf of +0.17 V. The equilibrium constant for the cell reaction is 5.5 105. What is the value of n for the cell reaction?
The solubility product for cerium(III) fluoride is 8.0 x 10^-16 (A) what is the molar solubility of Cerium (III) Fluoride in water?
Rhenium-186 is a ß-emitter with a half-life of 90.0 hours. How long would it take for the activity in a sample of this isotope to decay to exactly one-third of its original value?
A sample of N2(g) was collected over water at 25 degrees Celcius and 730 torr in a container with a volume of 340 mL. The vapor pressure of water at 25 degrees Celcius is 23.76 torr. What mass of N2 was collected?
A 17.9 g sample of an alloy at 98.0°C is placed into 127.2 g of water at 22.0 °C in an insulated coffee cup with a heat capacity of 9.2 J/K. If the final temperature of the system is 35.0°C, what is the specific heat capacity of the al
The vapor pressure of a water-insoluble organic substance is negligible at 100 degree C. Can this substance be purified by steam distillation? explain.
The molecule H2S2 has a linear arrangement of its atoms. Number all sulfur atoms along the chain from 1 to 4. Find the oxidation number of each sulphur in the molecule from the first to the fourth.
1944651
Questions Asked
3,689
Active Tutors
1422661
Questions Answered
Start Excelling in your courses, Ask a tutor for help and get answers for your problems !!
Question: The emotional impact of trauma and other stresses from infancy to adolescence is called:
When measuring participant self-esteem, we might want to have participants complete the measure twice, about a week apart,
The contributions of early theorists such as Atkinson, Shiffrin, and Tulving shaped the evolution of cognitive psychology.
Which behavior is a sign of GAD? Sleeping more than usual Excessive exercising Feelings of worthlessness Having difficulty staying focused on daily tasks.
Question: Which trait is a characteristic of individuals with positive mental health?
Write an initial psychiatric Evaluation, note, chief complaint, current Meds, substance use, past meds HPI, MSE,SI AND HI, psychosocial history,
Matthew has known he wanted to be a doctor since he was five years old. His father, aunt, grandfather, and cousin are all doctors.