Answer:
A
Explanation:
Iron has the ground state electronic configuration [Ar]3d64s2
Fe2+ has the electronic configuration [Ar]3d6.
In an octahedral crystal field, there are two sets of degenerate orbitals; the lower lying three t2g orbitals, and the higher level two degenerate eg orbitals. Strong field ligands cause high octahedral crystal field splitting, there by separating the two sets of degenerate orbitals by a tremendous amount of energy. This energy is much greater than the pairing energy required to pair the six electrons in three degenerate orbitals. Since CN- is a strong field ligand, it leads to pairing of six electrons in three degenerate orbitals
Answer: 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced molecular equation is:
Cooled, solidified lava is called igneous rocks.
Answer:
Metals and non-metals are substances that can be differentiated on the basis of various physical and chemical properties. Metals are the elements that are generally hard as strong metallic bond exists between the atoms. As against non-metals are the elements which are usually soft.