Use the periodic table to give the name and symbol for each of the following elements:
(a) the halogen in the same period as the alkali metal with 11 protons
(b) the alkaline earth metal in the same period with the neutral noble gas with 18 electrons
(c) the noble gas in the same row as an isotope with 30 neutrons and 25 protons
(d) the noble gas in the same period as gold

Explanation:

Noble gases are the gases which are present is group 18 of the periodic table.

(a) Sodium is the alkali metal that has 11 protons as its atomic number is 11. Sodium is present in group 1 and period 3 of the Periodic table. Therefore, noble gas present in period 3 is Argon.

(b) Argon is the noble gas that has 18 electrons and it is present in period 3. Hence, alkaline earth metal that is present in period 3 is magnesium.

(c) Manganese is the element that has atomic number (or protons) equal to 25 and its atomic mass (total protons + total neutrons) equal to 55. Manganese is present in period 4 and noble that is also present in period 4 is krypton.

(d) Gold is the element that is present in period 6. And, a noble gas which is also present in period 6 is Radon.