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This is one of our many quizzes on Periodic table. Click on this to access more such competitive quizzes on Inorganic Chemistry.

Periodic table Quiz 2

chemistry

   Which is the element that is placed in the ${{118}^{th}}$ position in the periodic table?

 The name for the element is given as a tribute to a nuclear physicist who worked on the discovery of the heavier elements.

  The element which has the atomic number $118$ is Oganesson. It is one of the newly discovered elements in the periodic table and is the last element in the periodic table too. The name was given as a mark of respect for the works of nuclear physicist Yuri Oganessian.

   What does the number $x$ written in the above right corner of an element symbol mean in the periodic table representation? $ \\ $<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/3c33d854-3b1b-4a4d-b1c2-22a4ef0d485c2685576729557573056.png"/>

 It gives an idea of the number of electrons present in the atom.

  The above given $x$ refers to the atomic number of the element. The atomic number of the element is equal to the number of protons present in the atom and it is equal to the number of electrons in the atom.

  Adithi was studying the diagonal relationship between the elements and she came to know that the metal present in chlorophyll also shows the diagonal relationship with an element $X$. The element $X$ is?

 The metal present in chlorophyll has an atomic number 12. 

 The element present in chlorophyll is magnesium and the magnesium belongs to group 2 and period 3. $Li$ is the element that shows the diagonal relationship with $Mg$. $Li$ is placed in group 1 and period 3 of the periodic table. So, the element $X$ is $Li$.

 Which is that alkaline earth metal that combines with hydrogen to form hydrolith?

  The alkaline earth metal will give a brick red colour during its flame test.

 Hydrolith is also called calcium hydride. Hydrolith is a saline hydride i.e. it has a salt-like structure. It is formed by the direct combination of hydrogen and calcium at a temperature range of about $300-{{400}^{\circ }}C$

  In an oxidation reaction, $Mg$ was converted to $\text{M}{{\text{g}}^{\text{2+}}}$ and Al was converted to $\text{A}{{\text{l}}^{\text{3+}}}$. Among these four species, which species will have the smallest size?

 The two ion species given are isoelectronic i.e. it has an equal number of electrons in them.

Both the elements Al and Mg belong to the same period. As we move across the period, the atomic radii decrease from left to right and the cations will be smaller than their parent atoms. We know the given species of ions are isoelectronic i.e. it has the same number of electrons. So, among isoelectronic species, the one which has the larger positive nuclear charge will be the smallest species i.e with the smallest radii. So, $\text{A}{{\text{l}}^{\text{3+}}}$ will have the least atomic radii.