You're dealing with a decomposition reaction in which potassium chlorate,
Now, chemical formulas contain numbers written as subscripts. These subscripts are used to describe how many atoms of a certain element you get in one molecule or one formula unit of said compound.
In this case, potassium chlorate has the following chemical formula
This means that one formula unit of potassium chlorate contains
- one atom of potassium,
#1 xx "K"#
- one atom of chlorine,
#1 xx "Cl"#
- three atoms of oxygen,
#color(red)(3) xx "O"#
Notice that the
In this case, the subscript
Jeep in mind that you can have cases where a subscript belongs to more than one element in a chemical compound.
For example, magnesium hydroxide,
When that is the case, the subscript is distributed to both these elements. So one formula unit of magnesium hydroxide would contain
- one atom of magnesium,
#1 xx "Mg"#
- two atoms of oxygen,
#color(blue)(2) xx "O"#
- two atoms of hydrogen,
#color(blue)(2) xx "H"#
Also, it's worth noting that stoichiometric coefficients are distributed to all the elements present in the chemical formula.
For example, the balanced chemical equation for the decomposition of potassium chlorate looks like this
#color(purple)(2)"KClO"_ (3(s)) -> 2"KCl"_ ((s)) + 3"O"_(2(g))#