Class 10SciencePeriodic Classification of ElementsMix Examples - Periodic Classification of Elements
MediumIn Mendeleev's Periodic Table,the elements were arranged in the increasing order of their atomic masses. However,cobalt with an atomic mass of $58.93 \ amu$ was placed before nickel having an atomic mass of $58.71 \ amu$. Give the reason for the same.
- ACobalt has higher chemical reactivity.
- BElements with similar properties were grouped together.
- CNickel was discovered later.
- DAtomic mass measurements were inaccurate at that time.
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Similar Questions
The electronic configurations of $4$ elements $A, B, C,$ and $D$ are as follows:
$A: 2, 1$
$B: 2, 2$
$C: 2, 8, 2$
$D: 2$
$(a)$ Which of these elements belong to the same group? Name them.
$(b)$ Which of these elements belong to the same period? Name them.
$(c)$ Which of these elements is inert? Name it.
$A: 2, 1$
$B: 2, 2$
$C: 2, 8, 2$
$D: 2$
$(a)$ Which of these elements belong to the same group? Name them.
$(b)$ Which of these elements belong to the same period? Name them.
$(c)$ Which of these elements is inert? Name it.
Medium
View SolutionThe following table shows elements represented by the letters $A, B, C, D, E, F, G$ and $H$.
Group $1$ $2$ $13$ $14$ $15$ $16$ $17$ $18$ Element $A$ $B$ $C$ $D$ $E$ $F$ $G$ $H$
$(i)$ Which of the elements has the atomic size:
$(a)$ biggest and $(b)$ smallest?
$(ii)$ Which element has valency:
$(a)$ $3$ and $(b)$ zero?
| Group | $1$ | $2$ | $13$ | $14$ | $15$ | $16$ | $17$ | $18$ |
| Element | $A$ | $B$ | $C$ | $D$ | $E$ | $F$ | $G$ | $H$ |
$(i)$ Which of the elements has the atomic size:
$(a)$ biggest and $(b)$ smallest?
$(ii)$ Which element has valency:
$(a)$ $3$ and $(b)$ zero?
Medium
View SolutionWhich one of the following does not increase while moving down the group of the periodic table?
Easy
View SolutionThe atomic number of $Na$ and $Mg$ is $11$ and $12$ respectively and they belong to the same period.
$(a)$ Which one would have smaller atomic size?
$(b)$ Which one would be more electropositive?
$(c)$ To which group would each one belong?
$(a)$ Which one would have smaller atomic size?
$(b)$ Which one would be more electropositive?
$(c)$ To which group would each one belong?
Medium
View SolutionMendeleev predicted the existence of certain elements not known at that time and named two of them as Eka-silicon and Eka-aluminium.
$(a)$ Classify these elements as metals,non-metals,or metalloids.
$(b)$ How many valence electrons are present in each one of them?
$(a)$ Classify these elements as metals,non-metals,or metalloids.
$(b)$ How many valence electrons are present in each one of them?
Medium
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