8 groups, 1 to 7 and most people call group 8 group 0 because the noble gases in group 0 have the outer electron shell full, so for example argon has 18 electrons, so it’s structure is 2.8.8 with its outer shell full. Also the number of the last shell defies what group it’s in, for example sodium is in group 1 so it’s structure is 2.8.1. Hope this helps.
F - 12.5
Cs - 87.5
F mass - 19
Cs mass - 132.91
Explanation:
2H2(g) + O2(g) → 2H2O(l ) Chemical equations give the following information about chemical reactions. Chemical equations show the formulas for the substances that take part in the reaction.
In an exothermic reaction, heat is released. ΔH for an exothermic reaction is negative. That means that the energy stored in the reactants is higher than the energy stored in the products.
The opposite is true for an endothermic reaction. Heat is absorbed, and <span>ΔH for an endothermic reaction is positive. This means that energy stored in the products is higher than the energy stored in the reactants.</span>
