. What is the main difference between the outer core and the inner core of the Earth? The inner core is mostly solid iron, the outer core is mostly liquid nickel. The inner core is solid iron and nickel and the outer core is liquid iron and nickel. The inner core is cooler because it's solid and the outer core is hotter and liquid. The inner core is hotter and liquid and the outer core is cooler and solid.

A) The inner core is mostly solid iron, the outer core is mostly liquid nickel

Explanation:

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.