A sodium chloride is like most of the ionic compounds
existing here on earth in which they are composed of having a high melting
point and by this, if found in underground rock deposits, they are usually in a
form of solid.
Explanation:
According to the law of the conservation of mass, 'mass is conserved in a chemical reaction. The mass cannot be created nor be destroyed in a chemical process'.
This law holds true for the burning of wood also. Although the wood burns to produce ash which weighs less than wood but also, it produces some soot and other gases and the sum of the masses of all these is equal to the sum of the masses of wood and oxygen that reacted with it.
Explanation:
Since, it is given that critical temperature of Argon is 150.9 K and critical pressure of Argon is 48.0 atm.
It is known that gas phase of neon occurs at 50 K. As the boiling point of Ar is more than the boiling point of neon which means that there is strong intermolecular force of attraction between argon molecules as compared to neon molecules.
This is also because argon is larger in size. As a result, induced dipole-induced dipole forces leads to more strength in Ar as compared to Ne.
Answer: The energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.
Explanation:
Given: n = 2
The relation between energy and 
orbit of an atom is as follows.
Substitute the values into above formula as follows.
The negative sign indicates that energy is being released.
Thus, we can conclude that the energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.
