Q. 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. 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 neural. Based on the above information answer the following questions:
(i) To which group or period of the periodic table do the listed elements belong?
(ii) What would be the nature of compound formed by a combination of elements B and F?
(iii) Which two of these elements could definitely be metals?
(iv) Which one of the eight elements is most likely to be found in gaseous state at room temperature?
(v) If the number of electrons in the outermost shell of elements C and G are 3 and 7 respectively, write the formula of the compound formed by the combination of C and G.
please also explain how we got the answer ....
Answers
i) 3rd period
ii) don't know...... sorry
iii) A and B
iv) G
v) CG∨3
If we read the question carefully, compound AG is NaCl or common salt which is commonly used in cooking.
Also, SiO2 is almost neutral.
(i) The listed chemicals belong to third period; it includes Na, Mg, Al, Si, P, S, Cl& Ar.
(ii) Compound formed by the combination of B (Mg) and F (S) will result in formation of salt called MgSO4
(iii) Compound A (Na) and B (Mg) are definitely metals as their oxides are basic in nature.
(iv) Element H (Ar), is likely to be found in gaseous state at room temperature as it is the 8th element of the group so it would have 8 electrons in its outermost shell which is the electronic configuration of an Nobel gas.
(v) They will form AlCl3 (Aluminium chloride).