I believe the answer is A.
3. The answer is B. 11. This is because there are the same amount of electrons and protons in an atom, and since there are 11 protons, there are 11 electrons.
5. The formula H2O means that there are 2 hydrogen atoms (because the 2 is after the H), and 1 oxygen atom, so the answer is C.
Hope this helps!
Answer:
10 liters of the 1% solution and 8 liters of the 10% solution she should mix to make the 5% solution.
Explanation:
Let the volume of 1% acid solution used to make the mixture = x L
So, the volume of 10% acid solution used to make the mixture = y L
Total volume of the mixture = <u>x + y = 18 L .................. (1)</u>
For 1% acid solution:
C₁ = 1% , V₁ = x L
For 10% acid solution :
C₂ = 10% , V₂ = y L
For the resultant solution of sulfuric acid:
C₃ = 5% , V₃ = 18 L
Using
C₁V₁ + C₂V₂ = C₃V₃
1×x + 10×y = 5×18
So,
<u>x + 10y = 90 .................. (2)</u>
Solving 1 and 2 we get,
<u>x = 10 L</u>
<u>y = 8 L</u>
Thus,
<u>10 liters of the 1% solution and 8 liters of the 10% solution she should mix to make the 5% solution.</u>