Question Discussion & Solution

The Correct Answer is Magnetic Force.

• Magnetic resonance imaging ( MRI) is one of the most popular medical imaging methods used in the world at many diagnostic centers.
• These MRI scanners use strong magnetic fields, gradients of the magnetic field, and radio waves to produce images of the organs inside the body.
• The magnetic force is a component of the electromagnetic force, one of nature's four basic forces, which is induced by charge movement.
• There would be a magnetic force of attraction between two objects containing charge in the same direction of motion, while objects in charge traveling in opposite directions have between them a repulsive force.

The correct answer is IPC Section 354 C.

• IPC Section 354 C provides safety and punishes the offender for voyeurism watching, capturing or sharing images of a woman engaged in private acts, without her consent, when she does not expect so.
• IPC Section 354 C:
  • Voyeurism Watching, capturing or sharing images of a woman engaged in private acts, without her consent, when she does not expect so is a punishable offence
  • 1 to 3 years of jail term + Fine for the first conviction.
  • 3 to 7 years jail term + Fine for a second or subsequent conviction

Additional Information

The correct answer is Hydrocarbons.

Key Points

• The compounds which are formed by the covalent bond between carbon & hydrogen, are known as hydrocarbons.
• These are also known as 'parent compound'.
• Carbon is placed in the Second period.
• The atomic number of carbon is 6 while the weight is 12.
• Carbon needs 4 electrons to complete the octet state and it is full filled by covalent bonds.

Additional Information

•  Examples of Hydrocarbon.
• Natural Gas:
  • Natural gas contains 97% of Methane.
  • It is a colourless highly flammable gaseous hydrocarbon.
  • It is used as fuel for generating electricity and heat.
  • Natural gas is a compressed form that is used as fuel for vehicles which is known as CNG.
  • This is used for making fertilizers also, mainly ammonia.
• Methane:
  • Methane was discovered by the Italian scientist Alessandro Volta between 1776-1778 while he was studying the gases found in marshy land.
  • Melting Point- -182.5 degree
  • Boiling point- -161.5 degree
  • Methane gas is colourless and is less dense than water.
  • This gas is highly inflammable. While burning with oxygen it has a bluish flame.

Explanation:

• One of the most important contributors to the early construction of the periodic table was Russian scientist Dmitri Ivanovich Mendeléev.
• Mendeleev Periodic Table was introduced in 1869, following the rejection of Newlands Octave Law.
• Elements were arranged in Mendeleev's periodic chart according to their fundamental property, atomic mass, and chemical characteristics.
• Only 63 elements were known at Mendeleev's time.
• Mendeleev discovered that the properties of elements are the periodic function of their atomic mass in a periodic pattern after analysing their qualities.
• He ordered the elements in the periodic table so that those with comparable properties were in the same vertical columns.
• He developed a periodic law based on this finding, which states:- “The periodic function of an element's atomic mass is its property.”
• Demerits -  
  1. He couldn't find hydrogen in the periodic chart.
  2. Moving from one element to the next caused an irregular increase in atomic mass. As a result, the amount of elements that have yet to be identified is unpredictable.
  3. Isotopes were not considered. Later on, isotopes of elements that defied Mendeleev's periodic law were discovered.​ 

Additional Information

Mendeleev left places for undiscovered elements. 

• scandium, gallium and germanium, discovered later, have properties similar to Eka–boron, Eka–aluminium and Eka–silicon, respectively. So undiscovered elements were named also by Mendeleevs. 
• It was not very strictly based on increasing order of atomic mass.  For example, cobalt (atomic mass 58.9) appeared before nickel (atomic mass 58.7) based on periodic properties. 
• Noble gases can easily get adjusted in Mendeleev periodic table even they were discovered after the periodic table. 

Hence, there is one such digit.