Its what the formula of a coupon between PB to plus plus to
Answer:
40%
Explanation:
We'll begin by obtaining the molar mass of MgO. This is illustrated below:
Molar Mass of MgO = 24 + 16 = 40g/mol
Observing the formula MgO, we have 1 atom of O in it.
The percentage composition by mass of oxygen in MgO is given by:
Mass of O/Molar Mass of MgO x 100
= 16/40 x 100 = 40%
Ans:
from the product / reactant solution
from the environment when no solution is involved
Endothermic reactions are those reactions that proceed with the absorption of heat energy. In this case, the enthalpy of the reactants i.e. the initial energy is lower than that of the products. Therefore, energy needs to be supplied in order to break the bonds in the reactants and allow the reaction to proceed. This energy can be absorbed either from the environment when no solution is involved or from the product reactant solution.
For example, electrolysis of water which produces H2 and O2 is an endothermic reaction. Here, energy is absorbed by water in the form of electricity (current) to split it into corresponding products.
Answer: Stochiometric coefficients
Explanation: The chemical equations must be balanced to follow the law of conservation of mass which says that the mass of products must be same as the mass of reactants.
This is a skeletal equation and needs to be balanced by adjusting the stochiometric coefficients. In order to keep the mass same, the number of atoms must be same on both sides.
2 electrons on the first ring, 8 on the second, and 3 on the third ring