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
abruzzese [7]
3 years ago
12

The half-life of potassium-40 is 1.3 billion years. If a rock that formed 2.6 billion years ago originally contained 5 grams of

potassium-40, about ____ grams of potassium-40 would be left in that rock today
Chemistry
1 answer:
pochemuha3 years ago
8 0

Answer: 1.25 grams of Potassium-40

Explanation: When the amount of a compound is consumed by half, the time passed is called "the half life". This term is particularly important in nuclear chemistry. Potassium-40 is an isotope of potassium element and it is radioactive. As a result, the consumption time of this radioactive isotope is valuable information since radioactive isotopes are detrimental to health and nature.

For example, in this question, within 1.3 billion years, half amount of the potassium-40 disappears. 2.6 billion years ago, there were 5 grams of potassium-40 and when 1.3 billion years pass, half of the 5 grams of potassium-40 will disappear and there will will be 2.5 grams of potassium-40 left (5 grams of potassium-5 grams of potassium*(1/2)[half amount]=2.5 grams of potassium-40 left). As a result, 2.5 grams of potassium-40 is the amount that is present 1.3 billion years ago (2.6 billion years-1.3 billion years [half-life]=1.3 billion years). There will be 1.3 billion years left until today, so we still have to calculate the amount disappeared in 1.3 billion years. Thus, half of the 2.5 grams must disappear in 1.3 billion years left (2.5 grams - 2.5 grams*(1/2)[half amount]=1.25 grams). Finally, we have 1.25 grams of potassium-40 left since 2.6 billion years ago.

You might be interested in
Bethany has a fish tank at her house. She uses the following data table to keep track of the nitrate and phosphate levels in the
malfutka [58]
<span>sudden increase of Nitrate and Phosphate in March to April that occurred, it causes the fish tank to produce algae</span>
6 0
3 years ago
Read 2 more answers
100 POINTS!!
elena55 [62]

Answer:

The correct matching of the air mass and the letters in the word bank are given as follows;

1. Warm and humid                   ↔       D

2. Extremely cold and dry        ↔       B

3. Cold and dry                         ↔       A

4. Cold and humid                    ↔       C

5. Warm and dry                       ↔        E

Where;

A Represents continental polar

B Represents Artic

C Represents Maritime Polar

D Represents Maritime Tropical

E Represents Continental Tropical

Explanation:

A. A continental polar is one that can be described as a cold and dry climate as the region is located at a further away from the oceanic water bodies that add humidity to the climate

B. The regions of the Artic and the Antarctic have very limited amount of precipitation every year because the air is very cold as well as dry

C. A polar climate is a cold climate region, while a maritime climate is humid.

Therefore, the maritime polar climate combines both cold and humid conditions

D. A warm and humid region has high rainfall and humidity, as such the maritime climate which are humid and the tropical climate, which are warm, combine to give a warm and humid climate

E. The continental tropical climate can be described as warm and dry, compared to the continental water bodies, due to the location being distant from and therefore, the absence of high moisture containing wind that comes from the oceans.

7 0
2 years ago
Read 2 more answers
How do you figure out molality
hodyreva [135]
*The molality of a solution is calculated by taking the moles of solute and dividing by
the kilograms of solvent* Basically if we had 1.00 mole of sucrose (it's about 342 3 grams) and
proceeded to mix it into exactly 1.00 liter water. It would dissolve and make sugar
water. We keep adding water, dissolving and stirring until all the solid was gone. We
then made sure everything was well-mixed.
What would be the molality of this solution? Notice that my one liter of water weighs
1000 grams (density of water = 1.00 g / mL and 1000 mL of water in a liter).
3 0
2 years ago
how many moles of sodium are needed to react with sulfuric acid to produce 3.75 moles of sodium sulfate according to the followi
anastassius [24]
Hello!
<span>
You'll need to react 7,5 moles of Sodium with sulfuric acid to produce 3.75 moles of sodium sulfate
</span>
First of all, you need to balance the reaction. The balanced reaction is shown below (ensuring that the Law of Conservation of Mass is met on both sides):

2Na + H₂SO₄ → Na₂SO₄ + H₂

Now, all that you have to do is to use molar equivalences in this reaction applying the coefficients to calculate the moles of Sodium that you'll need:

molesNa=3,75moles Na_{2} SO_4* \frac{2 moles Na}{1 mol Na_{2} SO_4} =7,5 moles Na 

Have a nice day!
5 0
3 years ago
The life function of transport in an organism
lesantik [10]

Answer:1

Explanation:

8 0
3 years ago
Other questions:
  • What is the the wavelength of light with a frequency of 230<br> Hz??
    13·1 answer
  • If a molecule contains two carbon atoms and four hydrogen atoms, what can you conclude about the bond between the carbon atoms?
    5·1 answer
  • How did incorporation of the Bill of Rights affect state governments​
    6·1 answer
  • A container of N2O3(g) has a pressure of 0.265 atm. When the absolute temperature of the N2O3(g) is tripled, the gas completely
    15·1 answer
  • What is the relationship between Celsius and kelvin
    12·1 answer
  • The elements carbon and sulfur are solids at room temperature. Can you reasonably predict that a compound of these two elements
    13·1 answer
  • 354.5 g of chlorine gas (MW = 70.9 g/mol) is held in a vessel with a fixed volume of 70. L.
    15·1 answer
  • What statements accurately describe matter? Check all that apply
    6·1 answer
  • Need help asap please!
    11·1 answer
  • There are 300 light particles in an airtight container. Which adjustment would increase the speed of the particles?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!