(20 13? Ningbo simulation) six elements, A, B, C, D, E and F, in which A, B, C, D and E are short-period main group elements. The relationship between them is as follows:

The highest positive valence+the lowest negative valence of element B =2, so B is the group ⅴ A element, and the number of electron layers outside the nucleus: B=C=2A, and A, B A+B=C are short-period main group elements, so A can only be the first periodic element, that is, A is hydrogen, B and CO are the second periodic elements, and B is nitrogen, because the outermost electron number: A+B = C.

(1) The common gas composed of two elements, A and B, is ammonia, and its electronic type is, so the answer is:

(2) The magnetic oxide of F is Fe3O4, and the hydrate corresponding to the highest valence oxide of E is H2SO4. The ionic equation of their reaction is Fe3O4+8h+= 2fe3+Fe2+4h2o. Phenolphthalein solution dripped into the glass tube of the carbon rod, and the solution near the carbon rod turned red, indicating that hydroxyl ions were generated at the electrode, so the electrode reaction was O2+2H2O+4e-=4OH-.

So the answer is: Fe3O4+8h+= 2fe3+Fe2+4h2o; O2+2H2O+4e-= 4OH-； ? Oxygen absorption corrosion;

(3) The salt composed of three elements, A, B and C, can react with AgNO3 solution to form white precipitate, and the chemical equation of the reaction is NH4? NO2+AgNO3 ═ AgNO3 ↓+NH4NO3, the salt solution is acidic at room temperature, indicating that the hydrolysis degree of NH4+ is greater than NO2-, so the relationship of ion concentration in the solution is C (NO2-> C (NH4+) > C (H+) > C (OH-).

So the answer is: NH4? no2+agno3═agno2↓+nh4no3； ? c(NO2-)> c(NH4+)> c(H+)> c(OH-)；

(4) The number ratio of the three ions in the common double salt formed by H, N, O, S and Fe2+ is 2: 1: 2, and its chemical formula is (NH4)2Fe(SO4)2. In order to test whether there is ferrous ion in this double salt, the experimental operation and related phenomena are as follows: take a small amount of this double salt in a test tube, add water to dissolve it, drop KSCN solution, and then.

So the answer is: (NH4) 2fe (SO4) 2; Take a small amount of double salt and dissolve it in water in a test tube, then add KSCN solution dropwise, and there is no obvious phenomenon. Then add fresh chlorine water dropwise, and the solution will turn red immediately, which proves that there is Fe2+ (or add sodium hydroxide solution, and the white precipitate will turn gray-green quickly and finally red-brown).