Which state of matter is characterized by ionized particles, no definite shape or volume, and good electrical conductivity?

Answer is: plasma.

There are five fundamental states of matter (gas, liquid, solid, plasma and Bose–Einstein condensate).  

In solid, molecules are closely packed, stiff and do not changes of shape or volume. Solid object (for example iron) does not take on the shape of its container.  

Liquids have definite volume, but no fixed shape.  

Gases (for example nitrogen and neon) not have definite volume and fixed shape, it depends on its container.  

Plasma is a an ionised gas with highly electrical conductivity.

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 !

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.