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
Liula [17]
3 years ago
14

A scientist is trying to determine whether a certain substance is radioactive. Which question would be most helpful to ask?

Chemistry
1 answer:
oksian1 [2.3K]3 years ago
3 0
Well a question to ask would be if the mass of the material has changed significantly as that would determine that the substance is radioactive or if there have been any high readings found by a Geiger meter in certain period of time

hope that helps 
You might be interested in
Exactly how much time must elapse before 16 grams of potassium-42decays, leaving 2 grams of the original isotope?(1) 8 × 12.4 ho
AleksandrR [38]
The answer is <span>(3) 3 × 12.4 hours
</span>
To calculate this, we will use two equations:
(1/2) ^{n} =x
t_{1/2} = \frac{t}{n}
where:
<span>n - number of half-lives
</span>x - remained amount of the sample, in decimals
<span>t_{1/2} - half-life length
</span>t - total time elapsed.

First, we have to calculate x and n. x is <span>remained amount of the sample, so if at the beginning were 16 grams of potassium-42, and now it remained 2 grams, then x is:
2 grams : x % = 16 grams : 100 %
x = 2 grams </span>× 100 percent ÷ 16 grams
x = 12.5% = 0.125

Thus:
<span>(1/2) ^{n} =x
</span>(0.5) ^{n} =0.125
n*log(0.5)=log(0.125)
n= \frac{log(0.5)}{log(0.125)}
n=3

It is known that the half-life of potassium-42 is 12.36 ≈ 12.4 hours.
Thus:
<span>t_{1/2} = 12.4
</span><span>t_{1/2} *n = t
</span>t= 12.4*3

Therefore, it must elapse 3 × 12.4 hours <span>before 16 grams of potassium-42 decays, leaving 2 grams of the original isotope</span>
7 0
3 years ago
Read 2 more answers
Why do waves move faster at higher temperatures and in a solid phase?
podryga [215]
<span>There is more energy and the particles are closer together.</span>
7 0
3 years ago
Read 2 more answers
What is the name of the molecular compound CBra?​
Fudgin [204]

Answer:

i think it is a Cobrotoxin

6 0
3 years ago
ΔH for the formation of CuCl2 from its elements is -220.1 kJ/mol. How many kJ are associated with the formation of 0.30 mole of
otez555 [7]
0.3 * - 220.1 = - 66.03kJ
3 0
3 years ago
Read 2 more answers
What is the answer? Please
Delicious77 [7]

Answer:

Parasitism

Explanation:

Parasitism occurs when two organisms interact, but while one benefits, the other experiences harm. Parasites harm their hosts, as with the tapeworm attaching itself to the intestine of a cow; the tapeworm absorbs the nutrients from the cow's diet, preventing them from being absorbed by the cow.

4 0
2 years ago
Other questions:
  • I need to know what a metal nonmetel and metalloid
    13·2 answers
  • What is the heat required to vaporize 650 grams of a liquid with a heat of vaporization of 723 joules/grams?
    14·1 answer
  • Calculate the heat (in J) required to raise the temperature of 3.02 g of solid silver from 22.3 degrees Celsius so solid silver
    13·1 answer
  • What do the elements in each pair have in common?
    9·1 answer
  • what is it called when more then one element is combined but do not loose their individual chemical properties
    13·1 answer
  • A sailor on a trans-Pacific solo voyage notices one day that if he puts 375. mL of fresh water into a plastic cup fresh water we
    8·1 answer
  • An object has a density of 4.5kg/mL and a mass of 3.56kg. What is the volume of the object in ml?
    10·1 answer
  • A plant with wilted flowers has osmotic pressure. A.equal B.high C.low​
    8·1 answer
  • if you react 28 grams of butene with excess hydrogen how many grams of butane would you expect to get
    12·1 answer
  • Scrieti 5 exemple de reactii prin care se obtin alcooli.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!