Name: Electronic Configuration of Elements
Uploaded: 2019-07-19
Duration: 6 min 6 s
Description: The number of protons in an atom is called its atomic number, represented by ‘Z’, while the sum of its protons and neutrons is called its mass number, given...

Question

Arrange the elements in the table in increasing order of their atomic weights. Arrange the elements in the table in increasing order of their atomic numbers. Did you get the same order of elements in both the cases?

Accepted Answer

Atomic weight of an element is the total number of proton and neutron in the nucleus. Proton and neutron have significant masses that make up the entire mass of an atom. Elements arranged in the increasing order of their atomic weights are as follows:

${}_{1}H^{1} < {}_{2}{He}^{4} < {}_{3}{Li}^{6.9} < {}_{4}{Be}^{9} < {}_{5}B^{10.8} < {}_{6}C^{12} < {}_{7}N^{14} <$

${}_{8}O^{16} < {}_{9}F^{19} < {}_{10}{Ne}^{22.2} < {}_{11}{Na}^{23} < {}_{12}{Mg}^{24.3} < {}_{13}{Al}^{27} <$

${}_{14}{Si}^{28.08} < {}_{15}P^{31} < {}_{16}S^{32.1} < {}_{17}{Cl}^{35.5} < {}_{19}K^{39.1} < {}_{18}{Ar}^{39.9} < {}_{20}{Ca}^{40.1}$

Atomic numbers are the total number of electrons present in an atom. Elements arranged in the increasing order of their atomic numbers are as follows:

${}_{1}H^{1} < {}_{2}{He}^{4} < {}_{3}{Li}^{6.9} < {}_{4}{Be}^{9} < {}_{5}B^{10.8} < {}_{6}C^{12} < {}_{7}N^{14} <$

${}_{8}O^{16} < {}_{9}F^{19} < {}_{10}{Ne}^{22.2} < {}_{11}{Na}^{23} < {}_{12}{Mg}^{24.3} < {}_{13}{Al}^{27} <$

${}_{14}{Si}^{28.08} < {}_{15}P^{31} < {}_{16}S^{32.1} < {}_{17}{Cl}^{35.5} < {}_{18}{Ar}^{39.9} < {}_{19}K^{39.1} < {}_{20}{Ca}^{40.1}$

No, the order of elements in both the cases are not the same as $Ar$ with atomic number $18$ is heavier than $K$ having the atomic number $19$ .

Group A	Element	$Li$	$?$	$K$
Group A	Atomic mass	$6.9$	$23$	$39.1$
Group B	Element	$Ca$	$Sr$	$Ba$
Group B	Atomic mass	$40.1$	$?$	$137.3$
Group C	Element	$Cl$	$Br$	$I$
Group C	Atomic mass	$35.5$	$?$	$126.9$

Group A	Element	$Li$	$?$	$K$
Group A	Atomic mass	$6.9 u$	$23 u$	$39.1 u$
Group B	Element	$Ca$	$Sr$	$Ba$
Group B	Atomic mass	$40.1 u$	$?$	$137.3 u$
Group C	Element	$Cl$	$Br$	$I$
Group C	Atomic mass	$35.5 u$	$?$	$126.9 u$

Group A	Element	$Li$	$?$	$K$
Group A	Atomic mass	$6.9 u$	$23 u$	$39.1 u$
Group B	Element	$Ca$	$Sr$	$Ba$
Group B	Atomic mass	$40.1 u$	$?$	$137.3 u$
Group C	Element	$Cl$	$Br$	$I$
Group C	Atomic mass	$35.5 u$	$?$	$126.9 u$

Arrange the elements in the table in increasing order of their atomic weights. Arrange the elements in the table in increasing order of their atomic numbers. Did you get the same order of elements in both the cases?

Important Questions on Periodic Classification of Elements

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