1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Digiron [165]
3 years ago
8

Mantles for gas lanterns contain thorium, because it forms an oxide that can survive being heated to incandescence for long peri

ods of time. Natural thorium is almost 100% 232Th, with a half-life of 1.405 ✕ 1010 y. If an average lantern mantle contains 200 mg of thorium, what is its activity (in Bq)?
Physics
1 answer:
maksim [4K]3 years ago
5 0

Answer:

The activity is 811.77 Bq

Solution:

As per the question:

Half life of Thorium, t_{\frac{1}{2}} = 1.405\times 10^{10}\ yrs

Mass of Thorium, m = 200 mg = 0.2 g

M = 232 g/mol

Now,

No. of nuclei of Thorium in 200 mg of Thorium:

N = \frac{N_{o}m}{M}

where

N_{o } = Avagadro's number

Thus

N = \frac{6.02\times 10^{23}\times 0.2}{232} = 5.19\times 10^{20}

Also,

Activity is given by:

\frac{0.693}{t_{\frac{1}{2}}}\times N

A= \frac{0.693}{1.405\times 10^{10}}\times 5.19\times 10^{20} = 2.56\times 10^{10}\ \yr

A = \frac{2.56\times 10^{10}}{365\times 24\times 60\times 60} = 811.77\ Bq

You might be interested in
8 colors according to their alphabetical order​
damaskus [11]

Answer:

8 colors in alphabetical order are

Black

blue

brown

Green

Orange

Pink

Purple

Yellow

Explanation:

6 0
2 years ago
PLEASE ANSWER, HURRY! THANKS :) A green object will absorb ____________________ light and reflect ____________________ light. Ex
olga55 [171]

Answer:

It will absorb yellow and reflect green

8 0
2 years ago
You are given 6 identical resistors, and allowed to combine them in any possible configuration to produce different equivalent r
tatyana61 [14]

Answer:your gay

Explanation:

gay

7 0
3 years ago
Eating 2500 Cal every day a friend of mine maintains a stable weight of 70 kg. One day, after eating 3500 Cal, he decided to do
Kaylis [27]

Answer:

Explanation:

Calories to be burnt = 3500 - 2500 = 1000 Cals .

Efficiency of conversion to mechanical work  is 25 % .

Work needed to burn this much of Cals = 1000 x 100 / 25 = 4000 Cals.

4000 Cals = 4.2 x 4000 = 16800 J  .

Work done in one jump = kinetic energy while jumping

= 1/2 m v²

= .5 x 70 x 3.3²

= 381.15 J .

Number of jumps required = 16800 / 381.15

= 44 .

4 0
2 years ago
A light wave from a star has a frequency of 6.67 * 100 Hz and a wavelength of 4.50 x 10 to the power of -7 m.
Juliette [100K]

Answer:

speed =wavelenght x frequency

v=4.5 x 10 to the -7 x 667=0.3 x 10 to the -4 m/s

speed= distance/time

time=distance/speed

t=4 x 10 to the 16/0.3 x 10 to the -4=13.33 x 10 to the 20 seconds

Explanation:

5 0
2 years ago
Other questions:
  • A sled is accelerating down a hill at a rate of 1 m s2 . If the mass of the sled is suddenly cut in half and the net force on th
    7·1 answer
  • A golfer on a level fairway hits a ball at an angle of 21° to the horizontal that travels 99 yd before striking the ground. He t
    7·1 answer
  • Under which condition would time periods of daylight and darkness be equal everywhere on Earth all year? A. if Earth revolved ar
    11·2 answers
  • Northrop aircraft developed and built a deceleration sled to test the effects of the extreme forces on humans and equipment. In
    7·1 answer
  • A frequently quoted rule of thumb in aircraft design is that wings should produce about 1000 n of lift per square meter of wing.
    8·1 answer
  • 2. Derive an expression for the final velocity of an object dropped from some height (h)
    11·1 answer
  • The famous cliff divers of Acapulco leap from a perch 35 m above the ocean. How fast are they moving when they reach the surface
    11·1 answer
  • Can someone plz answere my question<br> for science
    9·1 answer
  • A flashlight contains a battery of two cells in series, with a bulb of resistance 12 Ohms. The internal resistance of each cell
    8·1 answer
  • CCL4 is Non polar and NH3 is Polar? Why?​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!