B I think is right. Hope this helps!
Answer:
hydrogen is the chemical element with the symbol H and atomic number 1. with the standard atomic
Answer:
In the third tube, the concentration is 0.16 ug/mL
Explanation:
In the first step, the solution is diluted by 5. Then, the concentration will be
20 ug/mL / 5 = 4 ug/mL
Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:
4 ug /ml / 5 = 0.8 ug/mL
This solution is then diluted again by 5 and the concentration in the third tube will be then:
0.8 ug/mL / 5 = <u>0.16 ug/mL </u>
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Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:
Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL
The melting points of the compounds from the choices are listed below:
a. C25H52 -> +47 to +56 degrees celsius
b. Hg -> -38.83 degrees celsius
c. CaCl2 -> +772 degrees celsius
d. CuO -> +1326 degrees celsius
It is evident from the listed melting points above that mercury (Hg) has the lowest melting point. This is why mercury is liquid at room temperature.
3 answer for number 3.4 is the answer for number 4
