Answer:
Explanation:
The half-life of K-40 (1.3 billion years) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction
<u>half-lives</u> <u> t/yr </u> <u>Remaining</u>
0 0 1
1 1.3 billion ½
2 2.6 ¼
3 3.9 ⅛
We see that after 2 half-lives, ¼ of the original mass remains.
Conversely, if two half-lives have passed, the original mass must have been four times the mass we have now.
Original mass = 4 × 2.10 g = 
Answer:
IHD = 0
Explanation:
Given that
C₆H₁₅N
Number of carbon atoms(n) = 6
Number of hydrogen atoms(x') = 15
Number of nitrogen atoms = 1
There is nitrogen atoms then x = x' -1
The index of hydrogen deficiency given as

So


IHD = 0
The index of hydrogen deficiency is zero.
Answer:
Which wind blows cool air inland during the day? Sea Breeze
Which wind blows cool air toward the sea at night? Land Breeze
Which winds blow steadily from specific directions and over long distances? Global Winds
<h2>
Hello!</h2>
The answer is:

<h2>
Why?</h2>
Since there is not information about the solute but only its mass, we need to assume that we are calculating the molar concentration of a solution or molarity. So, need to use the following formula:

Now, we know that the mass of the solute is equal 3.5 moles and the volume is equal to 1500 mL or 1.5L
Then, substituting into the equation, we have:

Have a nice day!