They become more stable because they achieve a full outer shell of valence electrons with the magic number of 8.
Option (a) is correct.
A reducing agent is the one which loses electrons to other substance.
Here, Zn has oxidation number 0 in the L.H.S of the equation, but on R.H.S its oxidation number is +2 i.e. it Zn has donated two of its electrons to

.
Hence, Zn is the reducing agent here.
Electrons - they are the particles that determine the chemical properties of an element
Answer: The values for Ka and Kb for the species in solution must be known before a prediction can be made
Explanation:
1. If Ka is greater than Kb, the salt solution is acidic
2. If Ka is lesser than Kb, the salt solution is basic
3. If Ka is equal to Kb, the salt solution is acidic
Answer:
Covalent
Explanation:
In the carbon tetrachloride molecule, four chlorine atoms are positioned symmetrically as corners in a tetrahedral configuration joined to a central carbon atom by single covalent bonds