Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 49

EASY

9th CBSE

IMPORTANT

Earn 100

An element E is available in the form of two isotopes ${}_{15}^{31}E$ (75.8%) and ${}_{15}^{33}E$ (24.2%). The average atomic mass of E is:

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Important Questions on Structure of Atom

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 50

The average atomic mass of a sample

X

is

16.2 u

. The percentages of

{}_{8}^{16}X

and

{}_{8}^{18}X

in it are:

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9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 51

The average atomic mass of a sample X is

23.04 u

. The

%

ages of

{}_{11}^{23}X

and

{}_{12}^{24}X

in it are:

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 1

Explain why

{}_{2}^{3}{He}

and

{}_{1}^{3}H

are not considered isotopes.

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9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 2

Why do the isotopes of same element have similar chemical properties?

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Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 3

Why do elements have fractional atomic masses?

MEDIUM

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Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 4

Define valency on the basis of number of valence electrons in an atom.

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Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 5

Name an element, which has a duplet structure.

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9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4B>Q 6

What do you understand by the term isotope?