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2 years ago

Neutral atoms of neon (atomic number 10) have the same number of electrons as each of the following except:

Chemistry

2 answers:

4vir4ik [10]2 years ago

8 0

Answer : The correct option is, Ar

Explanation :

(1) The element is, $Na^+$

Atomic number of Na = 11

The general electronic configuration of Na is, $1s^22s^22p^63s^1$

The electronic configuration of $Na^+$ is, $1s^22s^22p^6$

The number of electrons in $Na^+$ = 10

(2) The element is, $Mg^{2+}$

Atomic number of Mg = 12

The general electronic configuration of Mg is, $1s^22s^22p^63s^2$

The electronic configuration of $Mg^{2+}$ is, $1s^22s^22p^6$

The number of electrons in $Mg^{2+}$ = 10

(3) The element is, $F^-$

Atomic number of F = 9

The general electronic configuration of F is, $1s^22s^22p^5$

The electronic configuration of $F^-$ is, $1s^22s^22p^6$

The number of electrons in $F^-$ = 10

(4) The element is, Ar

Atomic number of Ar = 18

The general electronic configuration of Ar is, $1s^22s^22p^63s^23p^6$

The number of electrons in Ar = 18

(5) The element is, $O^{2-}$

Atomic number of O = 8

The general electronic configuration of O is, $1s^22s^22p^4$

The electronic configuration of $O^{2-}$ is, $1s^22s^22p^6$

The number of electrons in $O^{2-}$ = 10

From this we conclude that, the option 1, 2, 3 and 5 have the same number of electrons as the neutral atom of neon. While in 'Ar' there are 18 number of electrons.

Hence, the correct option is, Ar

HACTEHA [7]2 years ago

6 0

The answer would be : Ar.

Hope this helps !

Photon

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2 years ago

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Explanation:

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Formula used :

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$\log \frac{I_o}{I}=\epsilon \times c\times l$

where,

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$\epsilon$ = Molar absorption coefficient

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$I$ = transmitted light

Given :

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3 years ago

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The first and second expressions are additions and subtractions. When adding two numbers, the accuracy of the result is given by the number of decimal places in it. The result should have as many decimal places as the input with the least number of decimal places.

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Therefore, the result should be rounded to one decimal place. Note that these units are compatible for addition, since they are all the same. The result should have the same unit (that is: $\rm m$ .)

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Therefore, the result should have only three significant figures.

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$\rm 4.51 \; cm \times 3.6666 \; cm \approx 16.5\; \rm cm^2$ . (Rounded to three significant figures.)

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3 years ago