(i) Name one halogen ,one metal ,and one 13 group element which is liquid at 30 o C. (ii) Compare the atomic size and ionization enthalpy of halogen group

the answer to your question is c.

if you read the house of usher you should know that the house was haunted

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l