Materials with ionic bonds tend to be more easily scratched.
Answer:
n = 4 there are 16 orbitals
Mole of electron required by
mole is 
- Faraday law expressed how the change that is been being produced by a current at an electrode-electrolyte interface is related and proportional to the quantity of electricity that is been used.
- There is one mole of electron required for 1 Faraday of electricity.
- Avogadro constant is

- Mole of electron can be calculated by dividing the number of electron by avogadro's constant.
=
= 
Therefore, it requires
Faraday of electricity for the 
Learn more at: brainly.com/question/1640558?referrer=searchResults
A indicator is a weak organic acid or a base which has shows different colors in acidic and basic mediums. The color change occurs when the weak acidic or basic indicator dissociates to give its respective conjugate base or conjugate acid.
Therefore the correct option would be Indicators are weak acids or bases.