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प्रश्न
(a) Write its electronic configuration and determine its valency.
(b) Is it more reactive or less reactive than Ca (atomic number 20)? Justify your answer giving reason.
(c) Is it a metal or a non-metal?
(d) Write the formula of its oxide.
उत्तर
(a) Electronic configuration: 2, 8, 2
Valency: 2
(b) The element X is less reactive than Ca (atomic number 20), because former one is smaller in size and has higher force of attraction between valence electrons and nucleus. Therefore, electrons are less involve in chemical reactions.
(c) Element X (atomic number 12) is a metal.
(d) The formula of its oxide is XO.
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संबंधित प्रश्न
Use Mendeleev’s Periodic Table to predict the formulae for the oxides of the following elements:
K, C, Al, Si, Ba.
Name three elements that have a single electron in their outermost shells.
Name two elements that have two electrons in their outermost shells.
State any three demerits of Mendeleev’s periodic table.
Explain in brief how Mendel interpreted his results to show that the traits may be dominant or recessive.
What are the demerits of Mendeleev’s periodic table?
Beryllium : alkaline earth metal : : sodium: _______
In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the Periodic Table later?
The properties of eka-aluminum predicted by Mendeleev are the same as the properties of a later discovered elements: ______
List the features of Mendeleev’s Periodic Table.
