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
ch4aika [34]
2 years ago
5

a sample that has a half life of 45 years take ____ for the count rate to drop from 600 cpm to 150 cpm

Chemistry
1 answer:
Bond [772]2 years ago
5 0

Answer:

90yrs

Explanation:

Half life is the time taken for half of an original radioactive material to decay by half.

For the sample;

    Half - life = 45yrs

  Original amount  = 600cpm

 

                 Start                                  Number of atoms    

                 0yrs                                                600cpm

                                   First half life

                 45yrs                                              300cpm

                                  Second half life

                 90yrs                                               150cpm

You might be interested in
Fill the three 3d subshells with the specified number of electrons.
lana66690 [7]

1. 5 electrons.

3d^{5}

  • Therefore, the 3d subshells blanks will be like this:
  • ↑ ↑ ↑ ↑ ↑

2. 6 electrons.

3d^{6}

  • The 3d subshells blanks will be:
  • ↑↓ ↑ ↑ ↑ ↑

3. 7 electrons.

3d^{7}

  • The 3d subshells blanks will be:
  • ↑↓ ↑↓ ↑ ↑ ↑

Hope you could understand.

If you have any query, feel free to ask.

8 0
2 years ago
I need the 3 questions !!! About Rubidium (Rb) <br><br> ASAP PLEASE DUE IN LIKE 20 min
hjlf

Answer:

  1. 419kJ/mol  
  2. 5,0,0,+12
  3. That catches fire spontaneously

Explanation:

1. Topic: Chemistry

ElementFirst Ionization Energy (kJ/mol) Lithium520Sodium496Rubidium403Cesium376According to the above table, which is most likely to be the first ionization energy for potassium?  

  • 536kJ/mol  
  • 504kJ/mol  
  • 419kJ/mol  
  • 391kJ/mol  
  • 358kJ/mol

2. Topic: Chemistry, Atom

The correct set of four quantum numbers for the valence electrons of the rubidium atom   (Z=37)  is:  

  • 5,1,1,+12  
  • 5,0,1,+12  
  • 5,0,0,+12
  • 5,1,0,+12

3. Rubidium and cesium are pyrophoric. Here the term pyrophoric means:

  • That hardly catches fire
  • That does not catch fire at all
  • That catches fire spontaneously
  • None of these
5 0
3 years ago
I build a fire and burn 3 logs. Apply the Law of Conservation of Matter
photoshop1234 [79]
Capture all of the smoke and weight it. it will weigh exactly the same before and after you burn it but will just be CO2 and H2O gas.
7 0
3 years ago
Pls help! I'll give u 10 points and the brainlest answer!!!​
alekssr [168]

Answer:

371km

Explanation:

the lower the more fuel there is

7 0
3 years ago
Read 2 more answers
Determine how much energy is needed to change 50 g of liquid water at 100°C to steam.
marin [14]

Answer:

Q=113,000J

Explanation:

Hello there!

In this case, since the vaporization process is carried out in order to turn a liquid into a gas due to the addition of heat, we can use the following heat equation involving the heat of vaporization of water or any other substance:

Q=m*\Delta _{vap}H

Thus, since this heat of vaporization for water is 2259.36 J/g, we plug in this amount to obtain the total energy for this process.

Q=50*2259.36 J/g\\\\Q=113,000J

Which is positive due to the necessity of heat.

Regards!

5 0
3 years ago
Other questions:
  • Potassium bromide is an ionic compound. If you dissolve potassium bromide in water and add electricity, what will happen? It wil
    10·2 answers
  • If you weigh 100 kg, how much would you weigh if all the water were removed from your body? A65 kg B45 kg C50 kg D35 kg
    9·1 answer
  • Imagine a friend is planning a rock-climbing trip. Write a note in the box explaining how gas exchange is affected at the top of
    11·1 answer
  • What mass of glucose (C6H1206) can form from
    8·1 answer
  • What does the word unicellular and multicellular mean? and What is the main difference between prokaryotes and eukaryotes?
    14·2 answers
  • calculate the atomic mass of element X, if it has 2 naturally occurring isotopes with the following masses and natural abundance
    8·1 answer
  • Use your periodic table to determine which element in the group below would be least likely to react with the other elements ?
    9·2 answers
  • PLEASE HELP AND DONT YOU DARE GIVE ME THE LINK
    15·1 answer
  • In the NCl3 molecules there are banded pairs of electrons and nonbonded pairs of electrons attached to central atom?
    9·1 answer
  • A sample of gas occupies a volume of 72.0 mL . As it expands, it does 141.2 J of work on its surroundings at a constant pressure
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!