Answer:
Take for example I₂ (iodine)
Explanation:
It has only a pair of electrons between the iodine atoms in order to gain a stable arrangement of 8 electrons in its outer shell. It is sharing them, so it's a covalent bond as a single iodine atom cannot be stable on its own. It's a halogen and is a single covalently-bonded diatomic molecule.
Similarly, take oxygen. IT needs two pairs of electrons just so it can reach a stable outer shell of 8 electrons. If it doesn't then it cannot be stabilised so it must be bonded with another oxygen atom and share two electrons.
Answer:
c. isotope number
Explanation:
Mass Number is the sum total of mass of protons and neutrons present in the nucleus of an atom. Generally they are being used in distinguishing isotopes. E.g Carbon - 12, Carbon - 13
Atomic Number is the number of protons. Every single element has it's unique atomic number and can be used in identification purpose. E.g Carbon - 6, Hydrogen - 1.
The correct option is option C. This is the symbol that is not necessary for the identification of a nuclide.