Answer:
<em>When molecular hydrogen (H2) and oxygen (O2) are combined and allowed to react together, energy is released and the molecules of hydrogen and oxygen can combine to form either water or hydrogen peroxide.</em>
Only when there is no product that is when a chemical reaction has not occured
Answer:
They are salts, ionic compounds
Explanation:
To know if they are covalent or ionic we need to check their difference in electronegativity. As an example mgcl2, mg has electronegativity of 1.2 and cl 3 so 3-1.2=1.8 which is bigger than 1.7 means it's ionic therefore they are salts
Answer:
physical change.
Explanation:
because it changes its physical attributes
