Answer:
The relation between the shielding and effective nuclear charge is given as

where s denote shielding
z_{eff} denote effective nuclear charge
Z - atomic number
Explanation:
shielding is referred to as the repulsion of an outermost electron to the pull of electron from valence shell. Higher the electron in valence shell higher will be the shielding effects.
Effective nuclear charge is the amount of net positive charge that valence electron has.
The relation between the shielding and the effective nuclear charge is given as
wheres denote shielding
z_{eff} denote effective nuclear charge
Z - atomic number
Yes, they are right.Very good hand writing! You did a very great job on showing your work.
Volume of the tank is 5.5 litres.
Explanation:
mass of the CO2 is given 8.6 grams
Pressure of the gas is 89 Kilopascal which is 0.8762 atm
Temperature of the gas is 29 degrees ( 0 degrees +273.5= K) so (29+273)
R = gas constant 0.0821 liter atmosphere per kelvin)
FROM THE IDEAL GAS LAW
PV=nRT ( P Pressure, V Volume, n is number of moles of gas, R gas constant, Temperature in Kelvin)
no of moles = mass/atomic mass
= 8.6/44
= 0.195 moles
now putting the values in equation
V=nRT/P
= 0.195*0.0821*302/ 0.8762
= 5.5 litres.
As the carbon dioxide gas occupies the volume os the tank hence volume of tank is 5.5 litres.
17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass