<span>The option A is correct answer. The isotopes are X and Y. The isotopes are those which have same atomic number but different mass number. Since atomic number has same number of protons or electrons. Thus, isotopes have same number of protons or electrons. Therefore, X and Y are isotopes.</span>
C. the square root of the mass of the particles.
<h3>Further explanation </h3>
Graham's law: the rate of effusion of a gas is inversely proportional to the square root of its molar masses or
the effusion rates of two gases = the square root of the inverse of their molar masses:

or

From this equation shows that the greater the mass of the gas, the smaller the effusion rate of the gas and vice versa, the smaller the mass of the gas, the greater the effusion velocity.
So if both gases are at the same temperature and pressure, the above formula can apply
Answer:
The answer to your question is 432 g of CO₂
Explanation:
Data
CaCO₃ = 983 g
CaO = 551 g
CO₂ = ?
Balanced reaction
CaCO₃ (s) ⇒ CaO (s) + CO₂ (g)
This reaction is balanced, to solve this problem just remember the Lavoisier Law of conservation of mass that states that the mass of the reactants is equal to the mass of the products.
Mass of reactants = Mass of products
Mass of CaCO₃ = Mass of CaO + Mass of CO₂
Solve for CO₂
Mass of CO₂ = Mass of CaCO₃ - Mass of CaO
Mass of CO₂ = 983 g - 551 g
Simplification
Mass of CO₂ = 432 g
Explanation:
Relative dating is used in determining a fossils approximate age comparing it with similar rocks and fossils whose age are known or formation of sedimentary rock . Whereas absolute dating is used in to determining the exact age of fossil by determining radiometric dating to measure the decay of isotopes, either within the fossil or more often the rocks associated to it.