<em>An example of a</em><em>n</em><em> </em><em><u>exothermic</u></em><em> </em><em>reaction is when metals react with oxygen to form metal</em><em> </em><em><u>Oxides</u></em>
<em><u>Hope</u></em><em><u> </u></em><em><u>this</u></em><em><u> </u></em>helped you- have a good day bro cya)
Answer:
A small positively charged nucleus surrounded by revolving negatively charged electrons in fixed orbits
Answer:
See below
Explanation:
Ammonium 
is not a molecular ion because it is just a poly-atomic ion. A molecular ion has a "negative or positive charge" as a whole but the positive charge on here is not on the whole. So, it is a poly-atomic ion and not molecular ion.
