On the first one it is supposed to be 18. when you have a +1 charge you subtract it once. how i got 18 tho was from the protons. there was 19 so i subtracted that with 1 and got 18. hope that helped! :)
btw i’m not the best at explaining, i’m sorry :/
<span><span>Mn<span>O<span>2<span>(s)</span></span></span>+<span>H<span>2<span>(g)</span></span></span>→Mn<span>O<span>(s)</span></span>+<span>H2</span><span>O<span>(g)</span></span></span></span>
A. Thermal energy good job
