In a displacement reaction, a more reactive element replaces a less reactive element from a compound. In a double displacement reaction, two atoms or a group of atoms switch places to form new compounds.
Explaination:
Displacement chemical reaction :
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal.
Fe + CuSO4 → FeSO4 + Cu. When zinc is added to a copper sulphate solution, it displaces the copper metal. ...
Zn + CuSO4 → ZnSO4 + Cu.
etc.
Double Displacement Chemical Reaction :
Double displacement reactions take place mostly in aqueous solutions wherein the ions precipitate and exchange of ions takes place. For example, when a solution of barium chloride is mixed with sodium sulphate, a white precipitate of barium sulphate is formed rapidly. These reactions are ionic in nature.
Here are some examples of double displacement reaction: AgNO 3 + NaCl → AgCl + NaNO.
2NaCl + CaSO4 → Na2SO4+ CaCl.
H2SO4 + 2LiOH ⇌ Li2SO4 + 2H2O.
Answer:
There are no unpaired electrons.
Explanation:
There are no unpaired electrons in the Lewis symbol for a nitride ion(
).The nitride ion has a charge of -3. The negative charge on the Nitride ion indicates a gain in electrons . Nitrogen has 5 valence electrons that is the number of electrons that are in its outer shell .The total number of electrons that the nitride ion has is equal to 5+3 = 8 electrons . Electrons usually appear in pairs and obey the octet rule therefore the nitride ion has four electron pairs no unpaired electrons.
Metals are the type of elements that are most likely to form more than one type of ion, for instance iron can form the ion of Fe^2+ or Fe^3+.
Sorry I came a lil late,
The answer to your question is, 2.
Hope this helps! :)