1 elements
2 they have same number of valence electrons
3 period
There is the same overall number of atoms of each element on the reactants side as on the products side, they are simply rearranged. Also, mass is conserved as atoms cannot be created or destroyed by a chemical reaction.
Answer:
Explanation:
so if the reaction is C2H4+3O2-->2H2O+2CO2
if there were 7 moles of C2H4:
(see the attachment)
Answer:
Endothermic
Explanation:
Because Endothermic is cold and exothermic is hot and if you are using an ice pack it would be Endothermic and if you were using something that was hot it would be exothermic
<span>2. Light energy does not require a medium through which to travel.
Hope this helps!</span>