Question

Fill in the blanks with the choices given in the brackets:
(i) The molecular formula of Aluminum oxide is _______ (\[Al{{O}_{3}}/A{{l}_{2}}{{O}_{3}}\])
(ii) The vertical columns in periodic tables are ________ (groups/periods.)
(iii) Group II metals are called _______ metals. (alkali/alkaline earth)
(iv) According to the modern periodic law, physical and chemical properties of the elements are the periodic functions of their _______ (atomic weight/atomic number).
(v) A carbonate that does not decompose on heating is _______(\[{{K}_{2}}C{{O}_{3}}\]/\[CaC{{O}_{3}}\])

Answer 1

Hint: (i) A chemical formula that speculates the kinds of atoms and a number of every kind in a molecule of a compound. (ii) There are 18 vertical columns in the periodic table. (ii) Elements of group II are harder and less reactive than the alkali metals of group I(iv) . The properties of the elements are reliant upon the atomic number due to electronic configuration of the elements. (v) Sodium carbonate and potassium carbonate are stable, rest other carbonates are not.


Complete answer:
(i)Since the general charge of a compound should consistently be equivalent to zero), we need 2 aluminum atoms and 3 oxygen atoms so as to adjust the charge and make the compound impartial. This implies that the chemical formula for aluminum oxide is essentially \[A{{l}_{2}}{{O}_{3}}\]. That is 2 aluminum particles for each 3 oxygen atoms.
(ii)The vertical segments on the periodic table are called groups or families due to their comparative similar chemical behavior. All the individuals from a group of elements have similar number of valence electrons and comparable chemical properties.
(iii)The alkaline earth metals make up Group 2 of the periodic table, from beryllium (\[Be\]) through radium (\[Ra\]). Every one of these components has two electrons in its peripheral energy level, which makes the alkaline earths reactive enough that they're seldom discovered alone in nature.
(iv)The modern periodic law expresses that the physical and chemical properties of the elements are the periodic necessities of their atomic numbers. Researchers orchestrated elements in expanding requests of their atomic numbers from left to directly over each line. (v)And researched that the elements having similar properties come after regular intervals.
The reaction is typically endothermic as heat is needed to break chemical bonds in the compound going through deterioration. The more receptive the metal is, the more troublesome it is to break down its mixes. Hence, sodium and potassium carbonates are not affected by heat.

Hence, the correct options are,
(i)\[A{{l}_{2}}{{O}_{3}}\]
(ii)Groups
(iii)Alkaline earth metals
(iv)Atomic numbers
(v)\[{{K}_{2}}C{{O}_{3}}\].

Note: Group 2 elements are called alkaline earth metals as they create “alkaline solutions", hydroxides, when react with water and their oxides are found in earth crust. Molecular formulas tell you how many atoms of each element are in a compound.