All chemical reactions have a conversation of mass and energy.
Because:- There are only two laws for conversation in a chemical reaction. The conversation of mass, no mass can be created nor destroyed. Also, the law of conversation of mass states that no energy can be created nor destroyed in a chemical reaction. The charge can obviously change because they can bond and change charges.
Theyre the big bunched up group in the middle of the periodic table
I believe its B. <span>The chemical formula for water H2O represents 2 hydrogen and 1 oxygen in the compound. </span>
MgCl2(s) + H2O(l) → MgO(s) + 2 HCl(g)
Using the standard enthalpies of formation given in the source below:
(−601.24 kJ) + (2 x −92.30 kJ) − (−641.8 kJ) − (−285.8 kJ) = +141.76 kJ
So:
MgCl2(s) + H2O(l) → MgO(s) + 2 HCl(g), ΔH = +141.76 kJ
A compound machine is that which is composed of two or more simple machines. Simple machines come in 6 basic types: (1) wheel and axle, (2) inclined plane, (3) wedge, (4) pulley, (5) screw, and (6) lever. Among the choices given above, the compound machine is the can opener for it is a combination of a wedge and a lever.