Electronic configuration: The distribution or arrangement of electrons of a molecule or an atom in molecular or atomic orbitals.
Ground state electron configuration: The distribution of electrons of an atom or molecule around the nucleus with lower levels of energy.
Now,
stands for Ruthenium with atomic number 44. It is a metal and thus, has ability to lose electrons and, becomes positively charged ion.
One can write the electronic configuration with the help of atomic number and Afbau principle, Pauli exclusion principle etc.
Ground electronic Configuration is as follows:

Soft Hand notation: ![[Kr]4d^{7}5s^{1}](https://tex.z-dn.net/?f=%5BKr%5D4d%5E%7B7%7D5s%5E%7B1%7D)
Now, when ruthenium loses two electrons then it becomes
, thus electron configuration becomes
Soft Hand notation: ![[Kr]4d^{6}](https://tex.z-dn.net/?f=%5BKr%5D4d%5E%7B6%7D)
The ground state electronic configuration of Ruthenium is
and when it loses two electrons, then electronic configuration becomes
(
)
Answer:
Mass of hydrogen gas evolved is 0.0749 grams.
Explanation:
Total pressure of the gases = p = 758 mmHg
Vapor pressure of water = 23.78 mmHg
Pressure of hydrogen gas ,P = p - 23.78 mmHg = 758 mmHg - 23.78 mmHg
P = 734.22 mmHg = 
Temperature of of hydrogen gas ,T= 25°C =298.15 K
Volume of hydrogen gas = V = 0.949 L
Moles of hydrogen gas =n
PV = nRT (Ideal gas equation )

n = 0.03745 mol
Moles of hydrogen gas = 0.03745 mol
Mass of 0.03745 moles of hydrogen gas = 0.03745 mol × 2 g/mol = 0.0749 g
Mass of hydrogen gas evolved is 0.0749 grams.
The distance covered will be:

The correct answer is
D).
To determine the number of moles of carbon dioxide that is produced, we need to know the reaction of the process. For the reaction of HCl and sodium carbonate, the balanced chemical equation would be expressed as:
2HCl + Na2CO3 = 2NaCl + H2O + CO2
From the initial amount given of sodium carbonate and the relation of the substances from the balanced reaction, we calculate the moles of carbon dioxide as follows:
0.2 moles Na2Co3 ( 1 mol CO2 / 1 mol Na2Co3 ) = 0.2 moles CO2
Therefore, the amount in moles of carbon dioxide that is produced from 0.2 moles sodium carbonate would be 0.2 moles as well.