Deepak Pandey

atomic number = 11 means, there are 11 electrons and 11 protons. mass number =23 indicates there 11 protons whose mass = 11 x 1 amu =11 amu and 23-11 = 12 neutrons whose mass = 12  x 1 amu =12 amu.
Hence in a sodium atom, there are 11 electrons, 11 protons and 12 neutrons.
Correct answer is option C


Note- mass of 1 proton = mass of 1 neutron = 1 amu

Density of population of country depends on two major factors and four minor factors. The factors responsible for the distribution of the population in India are as follows:
Major factors:
1. Physical Factors:
i. Relief: Mountains have rugged surface and are covered with thick forest along with harsh climate. However, Great Northern plains providing with suitable climate, level land, fertile soil along with good transport system.
ii. Climate: Climate of a region is existing pressure upon the human settlement. The desert region, mountainous regions are not densely populated because of too much cold climate.
iii. River-Systems: Rivers are providing with drinking water, water for irrigation, industrial water, helping navigation, producing hydro-power and making the land fertile by depositing silt.
iv. Geographical location: Geographical locations that favor development of modern infrastructures attracts more population.
v. Soils: India is primarily an agricultural country, fertile soil with favorable climate attracts a large number of population. River valleys which are filled with fertile soils are densely populated.
vi. Minerals: Minerals can exercise a considerable impact upon population distribution provided they are exploited.
vii. Vegetations: Human settlements respond differently to the varieties of natural vegetation forests, grasslands, marshes, and shrubs.
2. Non-physical/Economic factors:
i. Agriculture: Most of the people of India are engaged in agriculture. Agriculture is directly or indirectly attracting a large number of people. Areas haying fertile soils with irrigation facilities are densely populated.
ii. Industries: Industries are providing better economic support for the Indian masses.
iii. Well-developed Transport System: Transport system has a remarkable impact on population movement and distribution.
3. Minor-Factors:
i. Government Policies: Facilities provided by the Government can attract a huge population to a region.
ii. Historical factors: Historical factors are also responsible for the concentration population in a region.
iii. Religious factors: Religious places like Varanasi, Madura, Mathura, Nabadwip, Puri are densely populated because throughout the ages they are attracting a large number of population.
iv. Political factors: Political factors are also determining the density of population in a particular region. After the shifting of India's capital from Kolkata to Delhi people from different parts of India have settled here.