Answer:
A. Gas atoms subjected to electricity emit bright lines of light
Explanation:
When subjected to electricity, the electrons of a gas atom are <em>excited</em>. From that excited energy level, the electrons eventually go back to their initial state; this <u>transition</u> is done by emitting photons at a specific wavelength (causing an emission of bright lines of light).
Such is the mechanism of gas-discharge lamps tipically found in households.
Answer:
Na2SO4
Explanation:
In the crisscross method, we can write the correct formula for an ionic compound by crossing over the numerical value of each of the ion charges to now serve as the subscript of the oppositely charged ion. Subsequently, the signs of the charges are dropped and the correct formula of the ionic substance is obtained.
For sodium sulphate;
Na ^+ SO4^2-
By crisscrossing and dropping the signs to obtain the subscripts we now have;
Na2SO4
Combination or Synthesis Reaction. A combination of synthesis reaction is one. where a new product is synthesized by combination of two or three reactants.
Decomposition Reaction
Displacement or Replacement Reaction
Acid Base Reaction
Combustion Reaction
Answer:

Explanation:
Hello,
In this case, the undergoing chemical reaction is:

Thus, in terms of pressures, the rate becomes:

Thus, the rate of change for the partial pressure of ammonia turns out:
![r_{NH_3}=2*(-r_{N_2H_4})\\r_{NH_3}=2*[-(-70torr/h)]\\r_{NH_3}=140torr/h](https://tex.z-dn.net/?f=r_%7BNH_3%7D%3D2%2A%28-r_%7BN_2H_4%7D%29%5C%5Cr_%7BNH_3%7D%3D2%2A%5B-%28-70torr%2Fh%29%5D%5C%5Cr_%7BNH_3%7D%3D140torr%2Fh)
The rate of decrease of partial pressure of urea is taken negative as it is a reactant whereas ammonia a product which has 2 as its stoichiometric coefficient.
Best regards.