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JEE Main 20253 AprilMorning Shift

Exam: JEE Main
Year: 2025
Date: 3 April
Shift: Morning Shift
Subject: Chemistry
Chapter: Some Basic Concepts of Chemistry

JEE Main 2025 · 3 April · Morning Shift · Chemistry · Some Basic Concepts of Chemistry

Among 10^ -9 ~g (each) of the following elements, which one will...

Among

10^{-9} \mathrm{~g}

(each) of the following elements, which one will have the highest number of atoms? Element :

\mathrm{Pb}, \mathrm{Po}, \mathrm{Pr}

and Pt

Options

APo
BPr
CPb
DPt

Correct answer

B. Pr

Step-by-step solution

\text{ No. of atoms }=\frac{\text{ Massin } g}{\operatorname{Molar} \operatorname{Mas}(\mathrm{ g} / \mathrm{mol})} \times \mathrm{N}_{\mathrm{A}}

Therefore for the same Mass element having the least Molar mass will have the higher no. of atoms.-

\mathrm{M}_{\mathrm{Po}}=209

-

\mathrm{M}_{\mathrm{Pr}}=141

-

\mathrm{M}_{\mathrm{Pb}}=207

-

\mathrm{M}_{\mathrm{Pt}}=195

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