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
Nesterboy [21]
2 years ago
14

How long does it take for 87.5 % of each isotope to decay?

Chemistry
1 answer:
Zolol [24]2 years ago
7 0

Answer:

Kr-73 = 23.625 sec

Kr-74 = 10.0625 minutes (603.75 seconds)

Kr-76 = 12.95 hours (777 minutes)

Kr-81 = 1.8375 * 10^6 years

Explanation:

What you do is multiply each of those amounts by 7/8.

27 * 7/8 = 189/8 = 23.625

23/2 * 7/8 = 161/16 = 10.0625

74/5 * 7/8 = 518/40 = 259/20 = 12.95

210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6

You might be interested in
When the pressure on a solid is greatly increased, the volume of the solid shows almost no change.
Veronika [31]

Answer:

The volume of the solid shows no change

Explanation:

Pressure only affects gaseous system. This is because the force of cohesion between the gaseous molecules are negligible(i.e very small) and their molecules are far apart hence the gaseous molecules are easily compressed. But for solid, the Particles are very close and tightly packed together with a strong force of cohesion hence pressure has no effect on it. This account for the definite shape and definite volume of solid

4 0
2 years ago
Convert 12 kcal to joules
miss Akunina [59]

Answer:

50241.6

Explanation

8 0
3 years ago
Read 2 more answers
A vessel of volume 22.4 dm3 contains 20 mol h2 and 1 mol n2 ad 273.15 k initially. All of the nitrogen reacted with sufficient h
NikAS [45]

Nitrogen combine with hydrogen to produce ammonia \text{NH}_3 at a 1:3:2 ratio:

\text{N}_2 \; (g) + 3 \;  \text{H}_2 \; (g) \leftrightharpoons 2\; \text{NH}_3 \; (g)

Assuming that the reaction has indeed proceeded to completion- with all nitrogen used up as the question has indicated. 3 \; \text{mol} of hydrogen gas would have been consumed while 2 \; \text{mol} of ammonia would have been produced. The final mixture would therefore contain

  • 17 \; \text{mol} of \text{H}_2 \; (g) and
  • 2 \; \text{mol} of \text{NH}_3 \; (g)

Apply the ideal gas law to find the total pressure inside the container and the respective partial pressure of hydrogen and ammonia:

  • \begin{array}{lll} P(\text{container}) &= & n \cdot R \cdot T / V \\ & = & (17 + 2) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=&  1.926 \times 10^{3} \; \text{kPa} \end{array}
  • \begin{array}{lll} P(\text{H}_2) &= & n \cdot R \cdot T / V \\ & = & (17) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=&  1.723 \times 10^{3} \; \text{kPa} \end{array}
  • \begin{array}{lll} P(\text{NH}_3) &= & n \cdot R \cdot T / V \\ & = & (2) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=&  2.037 \times 10^{2} \; \text{kPa} \end{array}
6 0
3 years ago
Do you agree or disagree with the statement: "A rise of -7°C" means "a fall of 7°C"? Explain.
vazorg [7]

Answer:

i would agree

Explanation:

5 0
2 years ago
Why doesn’t a broken wineglass spontaneously fix itself, from a thermodynamic point of view?
Anarel [89]
C. Fixing a wineglass requires a large decrease in entropy.
4 0
3 years ago
Read 2 more answers
Other questions:
  • How did aristotles idea of matter differ from that of scientists
    11·1 answer
  • You evaporate all of the water from 100 mL of NaCl solution and obtain 11.3 grams of NaCl. What was the molarity of the NaCl sol
    15·1 answer
  • “Denitrifying” bacteria return molecular nitrogen gas (N2) back into the biosystem by a series of reductions. Identify the corre
    15·1 answer
  • In the 19th century James Joule, an English scientist, was the first to recognize the mechanical equivalent of heat as a specifi
    14·1 answer
  • 0.398 mol AgNO3 and 2.73 mol NH3 were added to enough water to give 1.00 L of solution at 25 °C. Calculate the equilibrium conce
    5·1 answer
  • Water has a large K, value.<br> True<br> False
    11·1 answer
  • The strength of the gravitational attraction depends on the mass of the objects involved and the distance between them. The grav
    5·1 answer
  • If 280cm3 of hydrogen diffuses in 40secs, how long will it take for 490cm3 of a gas x, whose vapor density is 25 to diffuse unde
    11·1 answer
  • The diagram is a model of one way that materials move into a cell.
    7·2 answers
  • What types of matter have the property of density?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!