Answer:
For a: The noble gas in the same period as germanium is Krypton.
For b: The alkaline earth metal in the same period as selenium is Calcium.
For c: The halogen in the same period as lithium is Fluorine.
For d: The chalcogen in the same period as cadmium is Tellurium.
Step-by-step explanation:
Periods are the horizontal lines in a periodic table.
Noble gases are the elements which are present in group 18 of the periodic table.
Germanium is present in Period 4 of the periodic table.
So, the noble gas in the same period as germanium is Krypton.
Alkaline earth metals are the elements which are present in group 2 of the periodic table.
Selenium is present in Period 4 of the periodic table.
So, the alkaline earth metal in the same period as selenium is Calcium.
Halogen are the elements which are present in group 17 of the periodic table.
Lithium is present in Period 2 of the periodic table.
So, the halogen in the same period as lithium is Fluorine.
Chalcogen are the elements which are present in group 16 of the periodic table.
Cadmium is present in Period 4 of the periodic table.
So, the chalcogen in the same period as cadmium is Tellurium.