<span>The periodic law states that the physical and chemical properties of elements are periodic functions of their "Atomic Numbers"
So, option B is your answer.
Hope this helps!
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Answer:
Explanation:
Hello there!
In this case, according to the given chemical reaction, it possible for us to set up the expression for the calculation of the enthalpy change as shown below:
Thus, given the values of the enthalpies of formation on the attached file, we obtain:
Best regards!
Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
Sorry for the long answer but hope this helps!
The # 4 is the only significant # in 400.. Trailing 0's r not significant unless there is a decimal.
in 0.7000, there are 4 significant #'s.
Percentage yield= actual yield/theoretical yield x100
So you would have to do-
15/22 x 100. Hope this helps!!
