Circuit is a closed loop through which current flows
I think the answer is 1s²2s²2p⁶. Since neon has an atomic number of 10, we know that it needs to have 10 electrons and since it is in the second row it cannot have any d electrons which makes the first option incorrect. The second option is incorrect because the 2s⁴ can't exist since s orbitals can only hold 2 electrons. The fourth option cannot be right because it again neon cannot have d electrons due to it being in the second row.
I hope this helps. Let me know if anything is unclear.
Answer: The molarity of the initial concentrated solution is 0.450 M
Explanation:
According to the dilution law,

where,
= Molarity of concentrated KOH solution = ?
= volume of concentrated KOH solution = 175 ml
= concentration of diluted KOH solution= 0.315 M
= volume of diluted KOH solution= 250 ml
Putting in the values, we get:


Thus the molarity of the initial concentrated solution is 0.450 M
D) reacts with oxygen
All other are physical properties.
The statement that best describes a solution is the option C: a mixture having a uniform composition where the components cannot be seen separately and all components are in the same state.<span> That is exactly what a solution is: a homogeneous mixture, the composition is uniform, but it can vary from one solution to other. The components must be in the safe phase, but it can be any phase: solid, liquid or gas. The most classical and clear example is the salt solution, NaCl. When you dissolve a spoon of NaCl in water you will not be able to distinguish nor separating the solute from the solvent, and the mixture will have uniform composition.</span>