Answer:
The answer to your question is letter b) He and Ne
Explanation:
Elements that have similar properties are placed in the same group in the periodic table.
So
A C and F These elements do not have similar properties because C is in group 4A and F is in group 7A. This is not the right answer.
B He and Ne These elements have similar properties becase they are in the same group (8A).
C Al and Si These elements do not have similar properties because Al is in group 3A and Si is in group 4A. This is not the right answer.
D N and S These elements do not have similar properties because N is in group 5A and S is in group 6A. This is not the right answer.
Answer:

Explanation:
Hello,
In this since one mole equals 6.022x10²³ particles of silver by means of the Avogadro's number, we can compute the moles in 4.27x10²² particles as shown below:

Best regards.
PH stands for "Potential Hydrogen" and the PH scale ranges from 0-14. PH refers to the ability to attract hydrogen ions.
The PH of a solution either indicates acidity of the solution or alkalinity of the solution. A solution which has PH 7 above is a base solution where a solution with PH less than 7 is an acidic solution.