Answer:
Explanation:
When we react Hydrochlorid Acid with zinc we have the following reaction:
2HCl(aq) + Zn(s) --> ZnCl2(aq) + H2(g)
The hydrogen gas formed is lost to the environment, so we can affirme that in the start we have the mass for all the H, Cl and Zn atoms in the solution, but after the reaction occurs, we have only the mass for the Cl and Zn atoms.
That's why the mass is less than the original.
The law that the student was told is only applied to closed environments.
Answer:
The answer is
<h2>38.85 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
density = 0.3456 g/cm³
volume = 112.4 cm³
The mass of the object is
mass = 0.3456 × 112.4 = 38.84544
We have the final answer as
<h3>38.85 g</h3>
Hope this helps you
Mainly made of metals and non-metals
Answer:
The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.
Explanation:
The energy of nth energy levels of the H atom is given as:
![E_n = -2.18 \times 10^{-18} \times \frac{1}{n^2} J](https://tex.z-dn.net/?f=E_n%20%3D%20-2.18%20%5Ctimes%2010%5E%7B-18%7D%20%5Ctimes%20%5Cfrac%7B1%7D%7Bn%5E2%7D%20J)
Energy of the seventh energy level = ![E_7](https://tex.z-dn.net/?f=E_7)
![E_7=-2.18 \times 10^{-18} \times \frac{1}{7^2} J](https://tex.z-dn.net/?f=E_7%3D-2.18%20%5Ctimes%2010%5E%7B-18%7D%20%5Ctimes%20%5Cfrac%7B1%7D%7B7%5E2%7D%20J)
![E_7=-2.18 \times 10^{-18} \times \frac{1}{7^2} J=-4.4490\times 10^{-20} J](https://tex.z-dn.net/?f=E_7%3D-2.18%20%5Ctimes%2010%5E%7B-18%7D%20%5Ctimes%20%5Cfrac%7B1%7D%7B7%5E2%7D%20J%3D-4.4490%5Ctimes%2010%5E%7B-20%7D%20J)
Energy of the seventh energy level = ![E_4](https://tex.z-dn.net/?f=E_4)
![E_4=-2.18 \times 10^{-18} \times \frac{1}{4^2} J](https://tex.z-dn.net/?f=E_4%3D-2.18%20%5Ctimes%2010%5E%7B-18%7D%20%5Ctimes%20%5Cfrac%7B1%7D%7B4%5E2%7D%20J)
![E_4=-2.18 \times 10^{-18} \times \frac{1}{16} J=-1.3625\times 10^{-19} J](https://tex.z-dn.net/?f=E_4%3D-2.18%20%5Ctimes%2010%5E%7B-18%7D%20%5Ctimes%20%5Cfrac%7B1%7D%7B16%7D%20J%3D-1.3625%5Ctimes%2010%5E%7B-19%7D%20J)
Energy of the light emitted will be equal to the energy difference of the both levels.
![E=E_7-E_4=-4.4490\times 10^{-20} J-(-1.3625\times 10^{-19} J)](https://tex.z-dn.net/?f=E%3DE_7-E_4%3D-4.4490%5Ctimes%2010%5E%7B-20%7D%20J-%28-1.3625%5Ctimes%2010%5E%7B-19%7D%20J%29)
![E=9.176\times 10^{-20} J](https://tex.z-dn.net/?f=E%3D9.176%5Ctimes%2010%5E%7B-20%7D%20J)
Wavelength corresponding to energy E can be calculated by using Planck's equation:
![E=\frac{hc}{\lambda }](https://tex.z-dn.net/?f=E%3D%5Cfrac%7Bhc%7D%7B%5Clambda%20%7D)
![\lambda =\frac{hc}{E}=\frac{6.626\times 10^{-34} Js\times 3\times 10^8 m/s}{9.176\times 10^{-20} J}=2.166\times 10^{-6} m=2166 nm](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7Bhc%7D%7BE%7D%3D%5Cfrac%7B6.626%5Ctimes%2010%5E%7B-34%7D%20Js%5Ctimes%203%5Ctimes%2010%5E8%20m%2Fs%7D%7B9.176%5Ctimes%2010%5E%7B-20%7D%20%20J%7D%3D2.166%5Ctimes%2010%5E%7B-6%7D%20m%3D2166%20nm)
The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.
Answer:
an increasng atomic number/ increasing proton count
Explanation: