Noble gases
Explanation:
Electronic configuration 1s² 2s² 2p⁶
The element belongs to the group of the noble gases.
- The noble gases have complete outer shell configuration of their atoms.
- we can infer that the configuration above is for an element in the p-block because the last sub-level filled is the p-orbital.
- The elements therefore belongs to the p-block
- The block is from group 111A to O
- Only the halogens and noble gases fits this picture from the option.
- The outer most p-subshell have three orbitals requiring 6 electrons to fill them up.
- This makes a complete and stable configuration.
- The highest energy level of 2 is also made up of 8 electrons, an octet.
- This is why we can conclude that they are noble gases.
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Answer:
Pupil, Cornea, Retina, and Lens
Explanation:
<h3><u>Answer</u>;</h3>
B. 3/2
<h3><u> Explanation;</u></h3>
Balance the chemical equation
2Al + 3Cl2 → 2AlCl3
We want to convert moles of AlCl3 to moles of Cl2
The conversion factor is 2 mol AlCl3/3 mol Cl2.
We choose the one that makes the units cancel:
x mol AlCl3 x (3 mol Cl3)/(2mol AlCl3) = x mol Al
The fraction for the molar ratio is 3/2.
Answer : The final number of moles of gas that withdrawn from the tank to lower the pressure of the gas must be, 0.301 mol.
Explanation :
As we know that:

At constant volume and temperature of gas, the pressure will be directly proportional to the number of moles of gas.
The relation between pressure and number of moles of gas will be:

where,
= initial pressure of gas = 24.5 atm
= final pressure of gas = 5.30 atm
= initial number of moles of gas = 1.40 moles
= final number of moles of gas = ?
Now put all the given values in the above expression, we get:


Therefore, the final number of moles of gas that withdrawn from the tank to lower the pressure of the gas must be, 0.301 mol.
Answer:
Alkaline
Explanation:
In an alkaline solution, red litmus paper turns blue. When an alkaline compound dissolves in water, it produces hydroxide ions, which cause the solution to become alkaline.