D should be the correct answer. isotopes are atoms that have the same atomic number (number of protons) but different atomic masses (number of protons and neutrons). isotopes also have the same number of electrons since atoms need to have equal numbers of protons and electrons to not be considered ions. Since the number of protons determines the chemical properties of the atom, we can say that all isotopes have the same chemical properties due to the fact that all isotopes have the same atomic number.
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I think the answer is A but i'm not sure
<u>Answer:</u> The fugacity coefficient of a gaseous species is 1.25
<u>Explanation:</u>
Fugacity coefficient is defined as the ratio of fugacity and the partial pressure of the gas. It is expressed as 
Mathematically,

Partial pressure of the gas is expressed as:

Putting this expression is above equation, we get:

where,
= fugacity coefficient of the gas
= fugacity of the gas = 25 psia
= mole fraction of the gas = 0.4
P = total pressure = 50 psia
Putting values in above equation, we get:

Hence, the fugacity coefficient of a gaseous species is 1.25
1st energy level can hold 2 electrons
2nd energy level can hold 8 electrons
3rd energy level can hold 8 or 18 electrons
Thickness of cooper sheet is 0.048 cm (Approx.)
Given that;
Density of copper = 8.96 g/cm³
Measures of copper sheet = 5.5 cm × 5.5 cm
Mass of of copper sheet = 12.96 gram
Find:
Thickness of cooper sheet
Computation:
Volume = Mass / Density
Volume of cooper = 12.96 / 8.96
Volume of cooper = 1.4464
Volume of cooper = 1.45 cm³ (Approx.)
Volume of cooper sheet = 5.5 cm × 5.5 cm x Thickness
5.5 cm × 5.5 cm x Thickness = 1.45
Thickness of cooper sheet = 0.04793
Thickness of cooper sheet = 0.048 cm (Approx.)
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