Q29 of 49 Page 145

A non-metal A which is the largest constituent of air combines with hydrogen on heating in the presence of Fe (as catalyst) and forms a gas

B. When this gas B is treated with H2SO4, compound C is formed which is broadly used as chemical fertiliser.


(i) Identify A, B and C.


(ii) Locate the position of A in the modern periodic table.


(iii) Which elements are present before and after the element A?


(iv) Write the electronic configuration of element A.

(i) The largest non-metal constituent of air is nitrogen (N) and it is present as N2 gas .It reacts with hydrogen in presence of Fe catalyst to give Ammonia (NH3). Ammonia reacts with conc. H2SO4 to give ammonium sulphate (NH4)2SO4.

Thus A= Nitrogen (N)


B=Ammonia (NH3)


C= Ammonium sulphate (NH4)2SO4


(ii) Element A is Nitrogen. It lies in the 2nd period and 15th group of the modern periodic table.


(iii) Carbon comes before nitrogen and oxygen comes after nitrogen in the 2nd period.


(iv) The atomic number of nitrogen is 7. So, its electronic configuration is 2,5.


More from this chapter

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27

X is an element of modern periodic table. It is surrounded by elements having atomic number 17, 34, 36 and 53.

(i) What is the atomic number of X?


(ii) Predict its position in the periodic table.


(iii) Which among these do not belong the same period?

 28

The position of five elements in the periodic table are shown below:


What are the number of valence electrons in B?


Identify the element(s) which


(i) will have the smallest atomic radius?


(ii) will be the most metallic?


(iii) will form basic oxide?


(iv) will show valency three?


(v) will show greatest tendency to gain electron?

 30

A teacher of Xth class, during teaching explains the importance of the music in our daily life. She was telling to her students that in the Indian system of music, there are seven musical notes in a scale sa, re, ga, ma, pa, da, ni. And in the west notations used are do, re, mi, fa, so, la, ti. The notes in a scale are separated by whole frequency intervals of tones. Every eighth note is similar to the first one and it is first note of next scale. A musician use these notes for composing music of a song.

Read the above passage carefully and answer the following questions accordingly.


(i) Is the situation discussed above is similar to something in chemistry? Explain.


(ii) What are the limitations of the above principle in case of chemistry?


(iii) What are the values you will infer from above passage?

 31

Every school has assembly Students stand in rows which should be straight, horizontally as well vertical. Each class stands in a single line, with schools. Each class has a name, e.g. class 1, 2, 3... etc. In general, height of students of class 1st is smallest and 12th is biggest. Everyone sings the prayer at the same time.

Read the above passage carefully and answer the following questions given below.


(i) Do you find similarity between rows of assembly with periodic table? Explain two points.


(ii) How can you compare qualities of students with elements of periodic table?


(iii) What values are inculcated during assembly of school?