Which half-reaction correctly represents reduction? *

a. S²⁻+2e⁻ ⇒ S⁰

b. S²⁻⇒S⁰ + 2e⁻

c. Mn⁷⁺+3e⁻⇒Mn⁴⁺

d. Mn⁷⁺⇒Mn⁴⁺₊3e⁻

You have 125g of a certain seasoning and are told that it contains 76.0 g of salt what is the percentage of salt by mass in this seasoning

How many molecules are found in 1.32 mol of nacl?

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.