Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells

Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but different number of electrons in their outermost shell. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water. This compound is added in a small amount to almost all vegetable dishes during cooking. Oxides of elements A and B are basic in nature while those of E and F are acidic. The oxide of D is almost neutral. Based on the above information,
answer the following questions:

  1. To which group or period of the periodic table do the listed elements belong?
  2. What would be the nature of compounds formed by a combination of elements B and F?
  3. Which two of these elements could definitely be metals and which are likely to be non-metals?
  4. Which one of the eight elements is most likely to be found in gaseous state at room temperature?
  5. If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write the formula of the compound formed by the combination of C and G.
  6. Which one of the eight elements is likely to be a noble gas?
  7. Which one of the eight elements would have the largest atomic radius?
  8. Which one of these eight elements is likely to be a semi-metal or metalloid?

Answer:

  1. Third period
    Group—1, 2, 13, 14, 15, 16, 17, 18 respectively.
  2. Nature of compound: Electrovalent/ionic.
  3. Metals—A and B; Non-metals—E, F, G
  4. G/H
  5. CG3
  6. H
  7. A
  8. D