Answer:
In our Sun, as in other stars, roughly 99.9% or so of all light emitted is emitted in a thin layer known as the photosphere, or light sphere. This is explained as follows. Interior to the photosphere the gas is ever denser and becomes far too opaque for any photon to emerge directly from that layer.
Explanation:
Answer : This reaction is an exothermic reaction.
Explanation :
Endothermic reaction : It is defined as the chemical reaction in which the energy is absorbed from the surrounding.
In the endothermic reaction, the energy of reactant are less than the energy of product.
Exothermic reaction : It is defined as the chemical reaction in which the energy is released into the surrounding.
In the exothermic reaction, the energy of reactant are more than the energy of product.
Enthalpy of reaction : It is the difference between the energy of product and the reactant. It is represented as
.
The balanced chemical reaction will be:

From the reaction we conclude that the heat energy is released during the reaction that means this reaction is an exothermic reaction.
Hence, the reaction is an exothermic reaction.
Answer:
Molecular Formula : NaNO2 or NNaO2 and Molecular Weight:
68.995 g/mol
Explanation:
Answer:
The right choice is c. Water molecules have a weakly positive hydrogen end.
Explanation:
The unequal sharing of electrons in water molecule gives a slight negative charge near its oxygen atom ( see image below) and a slight positive charge near its hydrogen atoms. A neutral molecule that has a partial positive charge at one end and a partial negative charge at the other, it is a polar molecule.
so
a. Water molecules have a nonpolar bond.
It is wrong choice because water has polar bond .
b. Water molecules have a weakly positive oxygen end.
Also, a wrong choice due to water molecule gives a slight negative charge near its oxygen atom.
c. Water molecules have a weakly positive hydrogen end.
This is the right choice.
d. Water molecules have two oxygen and two hydrogen atoms
It is wrong choice because water has one oxygen and two hydrogen atoms
So, the right choice is
c. Water molecules have a weakly positive hydrogen end.
Since water has a density of about 1g/mL, and we are assuming HCl and NaOH are mostly water, the total mass of the 2 solutions is 100 g.
Due to the conservation of mass, the mass of product must equal the total mass of reactant, therefore the final mass must also be 100 g.