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
My name is Ann [436]
4 years ago
6

Rn-222 has a half-life of 3.82 days. If 25.0 g of Radon-22 was originally present, approximately how many grams would be left af

ter 15 days?
Chemistry
1 answer:
horsena [70]4 years ago
6 0

Answer:

Approximately 0.39 g or 0.4 g if you're rounding up

Explanation:

15/3.82 = 3.92

Let's round that up to 4

That means 15 days is around 4 half lives

4 half lives means 1/16 of the original mass will be left

25/16 = 0.390625

You might be interested in
Plz help me its easy (: i give brainliest (:
EastWind [94]

Answer:

Bird eating worm: The bird gains energy from eating its proteins.

Plant recieving sunlight: The plant gains energy from the sunlight and transfers it into sugar and energy for it to continue its cycle.

Light bulb attached to battery: The lightbulb gains electricity and power from the battery until it runs out completely.

7 0
3 years ago
How many moles of pbr3 contain 3.68 × 1025 bromine atoms?
Tcecarenko [31]
The number  of Pbr3  that   contain   3.68  x10^ 25  bromine  atoms is  60.631  moles


      calculation

by  use of Avogadro  law constant 
that is,   1  moles =  6.02  x10^23   atoms

what   about  3.65  x10^25  atoms

by   cross  multiplication

= (1 mole  x 3.65 x  10 ^25  atoms)  /  ( 6.02  x10^23  atoms)  = 60.631  moles
atoms and  atoms  cancel  out  each  other
6 0
3 years ago
What is the rate of a reaction if the value of kis 0.1, [A] is 1 M, and [B] is 2 M?
mel-nik [20]

Answer:

D.  0.4 (mol/L)/S

Explanation:

You simply have to plug in the given values into the rate law.

Rate = k[A][B]

Rate = (0.1)(1)²(2)²

Rate = (0.1)(1)²(4)²

Rate = 0.4

8 0
3 years ago
What is paper chromatography? Calculate the Rr value of a colored dye that traveled 52 mm on a chromatography strip while the so
Karo-lina-s [1.5K]

Answer:

Paper chromatography is a basic technique of chromatography. It consist in the separation of the mixe components using a solvent.

Explanation:

Paper chromatography is a basic technique of chromatography. It consists in the separation of the mixed components using a solvent.

Paper chromatography consists of put some dot of the mix using a glass capillary into a specialized paper, generally made of cellulose, this is called a stationary phase.

Then you put this paper into a camera of glass named, chromatography camera, where previously contain a solvent. The solvent also know as a mobile phase, the type can be defined before the test and involves a study of the kind of the mix, and the compound you want to separate.

The chromatography camera has to be closed all the time during the test, and you can't move at all because the movement of the solvent can alternate the result.

Very often, the solution of the solvent is a mix of different liquid substances with different polarities.

When the stationary phase put into the camera, the solvent starts to move up over the paper, until the separation of the compounds is observable.

the Rf is a value who relates the move of the mobile phase with the move of the distance traveled by the substance tested.

To undersant the paper chromatography, you can watch the images attached.

The first is an image of the chromatography camera.

The second one is an image of a cellulose paper after the chromatography is done. You can watch the dots who indicates the traveling of the compound across the paper.

The third one can show you the evolutions of paper chromatography, from the beginning to the end.

To calculate the Rf value you have to use the equation:

Rf = distance traveled by the substance/distance traveled by the solvent/

<u>Rf = 52mm/81mm =0.64</u>

<u></u>

3 0
3 years ago
Choose the element that is more reactive: oxygen or argon.
Mazyrski [523]
I choose oxygen because
7 0
3 years ago
Other questions:
  • Soil shows what evidence of life
    9·1 answer
  • The formation of glaciers is directly controlled by climate. True False
    11·2 answers
  • How does temperature change in the troposphere differ from the stratosphere?
    12·1 answer
  • A student places a 12-gram cube of ice inside a container. After six hours, the student returns to observe the contents of the c
    10·2 answers
  • What are some reasons the human population increased greatly in the past<br> couple hundred years?
    12·1 answer
  • A fertilized egg cell develops into a(n) _________
    10·1 answer
  • 4 Compare and contrast the reactants and products in the two combustion
    8·1 answer
  • NO GO*GLE ANSWERS PLEASE!
    6·1 answer
  • Hi how are you guys doing today???
    15·2 answers
  • An ion of a single pure element always has an oxidation number of ________. a. 1 b. magnitude equal to its atomic number c. 0 d.
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!