Answer:
C. Fluorine because the model has 9 protons which is represented by the atomic number
Explanation:
We usually identify an element by the number of protons in them. The number of protons is the atomic number of an atom.
- Every atom has a specific number of protons in them.
- This number of protons is the atomic number.
- According to the periodic law, atoms are arranged on the periodic table based on their atomic number.
- The given fluorine atom has 9 protons which represents the atomic number of the atom.
- This way, the given number clearly shows the right model for identifying the chemical specie.
Answer:
n = 3 to n = 5
Explanation:
According to the Bohr's model of the atom, electrons in an atom absorb energy to move from a lower to higher energy level.
We must note that as we progress away from the nucleus, the energy levels of electrons become closer together. The energy difference between successive levels decreases and the wavelength of light associated with such transitions become longer.
Hence,the absorption of light of the longest wavelength corresponds to n = 3 to n = 5
.
Answer:
2.15
Explanation:
For this question, we have to remember the <u>pH formula</u>:
![pH~=~-Log[H_3O^+]](https://tex.z-dn.net/?f=pH~%3D~-Log%5BH_3O%5E%2B%5D)
By definition, the pH value is calculated when we do the -Log of the concentration of the <u>hydronium ions</u> (
). So, the next step is the calculation of the <u>concentration</u> of the hydronium ions. For this, we have to use the <u>molarity formula</u>:

We already know the number of moles (0.0231 moles) and the volume (3.33 L). So, we can plug the values into the molarity formula:

With this value, now we can calculate the pH value:
![pH~=~-Log[0.00693~M]~=~2.15](https://tex.z-dn.net/?f=pH~%3D~-Log%5B0.00693~M%5D~%3D~2.15)
<u>The pH would be 2.15</u>
I hope it helps!
<span>Metals tend to lose electrons and form electro-positive ions / cations.</span>