This is basics of organic chemistry - the element that has atoms that can bond with each other to form ring, chain, and network structures is (3) carbon.
The other elements available above cannot form such structures, whereas carbon, which is abundant in nature, can.
In an ionic compound the atoms are linked via ionic bonds. These are formed by the transfer of electrons from one atom to the other. The atom that loses electrons gains a positive charge whereas the atom that accepts electrons gains a negative. This happens in accordance with the octet rule wherein each atom is surrounded by 8 electrons
In the given example:
The valence electron configuration of Iodine (I) = 5s²5p⁵
It needs only one electron to complete its octet.
In the given options:
K = 4s¹
C = 2s²2p²
Cl = 3s²3p⁵
P = 3s²3p³
Thus K can donate its valence electron to Iodine. As a result K, will gain a stable noble gas configuration of argon while iodine would gain an octet. This would also balance the charges as K⁺I⁻ creating a neutral molecule.
Ans: Potassium (K)
Principal Energy Light Type of sub level Maximum number of electrons
P 8
2
S 18
3
P
Hope It really Helps
Answer:
As any molecular or ionic compound, 0 net charge, as a hypothetical diatomic cation, 2+
Explanation:
The question states that this is a compound, and any molecular or ionic compound would have a net charge of 0.
However, such a compound doesn't exist. Francium generally exists in nature having a 1+ charge in its cation form. Combining two francium ions would result in a 
species which is simply a diatomic ion but not a compound.
Answer:
Color Changes. A change in color often indicates a chemical change.
Temperature Changes. Changes in temperature might also indicate a chemical change has occurred.
Precipitates. The formation of a precipitate is a sign that a chemical change has occurred.
Light Emission.
Gas Production.
Explanation:
