Answer:
A
Explanation:
The purpose of the periodic table was to organize elements as they were discovered into periods and groups, according to their properties. It was not just a naming of elements, as a list.
Answer:
lower mantle
Explanation:
because the core and the crust are solid.
Answer:
Red light has the longest wavelength
Explanation:
Red light is emitted when a high energy state electron drops from high energy level 3 to low energy level 2. Red light has the longest wavelength and lowest energy. It is a know fact that the shorter the drop within energy levels, the lesser the energy.
Answer: The mole ratio of sodium to sodium chloride 2:2.
Explanation:
As the given reaction equation is as follows.
Here, 2 moles of sodium reacts with 1 mole of 
and leads to the formation of 2 moles of NaCl.
This means that 2 moles of sodium gives 2 moles of NaCl on reaction with chlorine.
Hence, the ratio of moles of sodium to sodium chloride is 2:2.
Thus, we can conclude that the mole ratio of sodium to sodium chloride 2:2.
