« previous next »

Author Question: A 1.0-mol sample of an isotope is decaying with a half-life of 28 y. After 61 y, how many moles of ... (Read 83 times)

genevieve1028

  • Hero Member
  • *****
  • Posts: 601
on: Jul 29, 2018
A 1.0-mol sample of an isotope is decaying with a half-life of 28 y. After 61 y, how many moles of this isotope are left and what is its activity in Bq?
 
  What will be an ideal response?

Question 2

What is the steady state rate of heat flow through a pane of glass that is 40.0 cm by 30.0 cm with a thickness of 4.00 mm when the outside temperature of the glass is -10.0C and its inside temperature is 25.0C?
 
  The thermal conductivity of glass is 0.105 W/(mK), the specific heat of glass is 0.180 cal/(gC), and 1 cal = 4.190 J.
  A) 3.81 W B) 110 W C) 24.2 W D) 47.3 W E) 18.6 W


Silverbeard98

  • Sr. Member
  • ****
  • Posts: 355
Reply #1 on: Jul 29, 2018
Answer to Question 1

0.22 mol, 1.0  1014 Bq

Answer to Question 2

B


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Opium has influenced much of the world's most popular literature. The following authors were all opium users, of varying degrees: Lewis Carroll, Charles, Dickens, Arthur Conan Doyle, and Oscar Wilde.

Did you know?

Drugs are in development that may cure asthma and hay fever once and for all. They target leukotrienes, which are known to cause tightening of the air passages in the lungs and increase mucus productions in nasal passages.

Did you know?

Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.

Did you know?

According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.

Did you know?

Patients who cannot swallow may receive nutrition via a parenteral route—usually, a catheter is inserted through the chest into a large vein going into the heart.

Diagram of the life cycle of Plasmodium falciparum, the causative agent of malaria Diagram of the life cycle of Plasmodium falciparum, the causative agent of malaria
Fossils Give Us a View of Past Life Fossils Give Us a View of Past Life
A typical spectrum with peaks representing the peptide fragments generated from a sample A typical spectrum with peaks representing the peptide fragments generated from a sample
palaeous life palaeous life
A sample flow sheet. A sample flow sheet.
Sample Size Affects Sampling Error Sample Size Affects Sampling Error
Video: Hormonal feedback loop components & Glucagon (glycogenolysis and gluconeogenesis)

For a complete list of videos, visit our video library