Question Discussion & Solution

The correct answer is 18 Groups and 7 Periods.

• Modern Periodic Table has 18 Groups and 7 Periods.
• It has 118 Elements.
• Each of the tables has a vertical row is called groups. Elements in groups have similar chemical and physical properties because they have the same number of outer electrons.
• Each of the tables has horizontal rows is called periods. During a period, a gradual change in chemical properties occurs from one element to another.
• It was given by Dmitri Mendeleev.
• The Structure of it is like a bird Grid.
• The Modern Periodic table is used to organize all the known elements.
• Advantages of Modern Periodic Table:- 
  •  It is easier to remember the properties of an element if its position in the periodic table is known.
  • It made the study of Chemistry Systematic and Easy.

Modern Periodic Table:-

The correct answer is Natural Gas.

Key Points

•  Fossil Fuel: Fossil Fuels are the fuels generated from the residues of living organisms (which remained buried under the earth for millions of years).
  • Examples: Coal, Petroleum, and Natural gas.
  • They are also known as Non-Renewable Natural Resources.​

 Additional Information

• Natural Gas: It is considered the best fuel because of the inflammable nature of its constituents(83% methane and 16%ethane).
  • It is used in the production of artificial chemical fertilizers. 
• Coke: It is obtained by the strong heating of coal in the absence of air as a residual substance. 
  • It contains 80-85% carbon.
  • Coke is used in the extension of metals as a reducing agent.
• Producer Gas: It is a mixture of nitrogen and carbon monoxide(in 2:1 ratio).
  • It is used in the manufacture of glass and for metallurgy. 

The correct answer is Calcium Carbonate.

Key Points

• The chief component of the nacre that constitutes the pearl is aragonite (CaCO₃).
• Nacre also contains a small amount of conchiolin, a hornlike organic substance (albuminoid) that is the main constituent of the mollusc's outer shell.
• Pearl also contains Magnesium Carbonate(MgCO₃) along with Calcium Carbonate.

Additional Information

• Calcium carbonate is a common substance found in rocks as the minerals calcite and aragonite and is the main component of eggshells, snail shells, seashells, and pearls. 
• The Molar Mass of Calcium Carbonate is 100.0869 g/mol.
• Melting point: 825 °C.

• The Best example of Run time polymorphism is Function Overriding
• Function Overloading is the example of Compile time polymorphism
• Protected is an Access modifier  

Important Point

Compile-time polymorphism

It means binding is occurring at compile time It can be achieved through static binding. If a class has multiple methods having the same name but different in parameters, it is known as Method Overloading.

Run time polymorphism

At run time we came to know which method is going to invoke It can be achieved through dynamic binding. If subclass (child class) has the same method as declared in the parent class, it is known as method overriding

Access Modifiers

It specifies the accessibility or scope of a field, method, constructor, or class. There are three types of Access modifiers

• Public: The methods or data members that are declared as public can be accessed anywhere in the program.
• Private:  The methods or data members declared as private are accessible only within the class in which they are declared.
• Protected: The methods or data members declared as protected can accessible within the same class or class which is inherited from it.

The correct answer is Bundi.

• 'Navlakha' lake is located in Bundi.

Key Points

• Other lakes in Bundi
  • Kanak Sagar
    • ​Several migratory birds can be seen here.
  • Naval Sagar
    • ​Nawal Sagar Lake is an artificial lake that is a major tourist attraction.
  • Jait Sagar
    • ​It is located close to the Taragarh Fort.

​Additional Information

• Naulakha Bawdi:
  • Naulakha Bawdi was built in 1586 AD.
  • It was built by Patrani Premal Devi of Maharawal Assochan.
  • This step-well is located in the Dungarpur district of Rajasthan.​​​​​​​
  • Facts related to the Naulakha 
    • Naulakha Mahal - Udaipur 
    • Naulakha Lake - Bundi 
    • Naulakha Burj - Chittorgarh 
    • Naulakha Bawdi - Dungarpur 
    • Naulakha Gate - Ranthambore 
    • Naulakha Temple - Pali