What is the main difference between an internal combustion engine and an external combustion engine?

1)the burning of fuel occurs inside the cylinder with the piston in an external combustion engine.

2)an internal combustion engine doesn't have a cylinder and a piston.

3)the burning of fuel occurs inside the cylinder with the piston in an internal combustion engine.

4)an external combustion engine doesn't have a cylinder and a piston

The correct answer is option (3).

Explanation:

Internal combustion engine: An engine which generates motive power by burning the fuel with air inside the engine. Heat produced is used to move piston or to perform other work as they expand.

External combustion engine : An engine where motive power is generated by providing the heat to the fluid present inside the engine from the external source. Here combustion of the fuel is not inside the engine.

Hence,the correct answer is option (3).

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !