Magnesium. You can count the electrons in each level and because the number of electrons is the same with protons you have the atomic number based of which you can get the element in the periodic table
Answer:

Explanation:
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In this case, according to the given information, it turns out possible for us to solve for the molarity of the KOH solution by knowing this base react in a 1:1 mole ratio with nitric acid, HNO3; thus, we can write the following equation, as their moles are the same at the endpoint:

Which in terms of molarities and volumes is:

Thus, we solve for the molarity of the base (KOH) to obtain:

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Water or also known as H2O
you are right on all the ones you did