तत्वों का ब्लॉकों मे विभाजन Lec 2 | Trick to learn elements 11th Chemistry Chapter 3 By Poonam Ma'am

Read the given letter number sequence carefully and answer the question given below: J K P D F G H 6 9 2 8 Q E M 7 4 3 Z Y B T 5 4 2 3 In the arrangement of letters and numbers given below, first all the numbers are arranged in the descending order and then all the letters are written in the alphabetical order. Then which letter/ number will be fourth to the left of the 11th element from the left end in the new arrangement? 1) K 2) 3 3) B 4) 1 5) None of these

The average of thirteen numbers is 47. The average of the first three numbers is 39 and that of the next seven numbers is 49. The 11th number is two times the 12th number and 12th number is 3 less than the 13th number. What is the average of 11th and 13th numbers? तेरह संख्याओं का औसत 47 है | पहली तीन संख्याओं का औसत 39 है तथा अगली सात संख्याओं का औसत 49 है | 11वीं संख्या 12वीं संख्या से दोगुनी है तथा 12वीं संख्या 13वीं संख्या से 3 कम है | 11वीं और 13वीं संख्याओं का औसत ज्ञात करें |

Given below are some of the elements of first group Li, Na, K (Their atomic numbers are 3, 11 , 19 respectively and they belong to 2nd, 3rd and 4th period respectively). Arrange these in the decreasing order of metallic character exhibited by them.

The average of twelve numbers is 55.5. The average of the first four numbers is 53.4 and that of the next four numbers is 54.6. The 10th number is greater than the 9th number by 3 but lesser than the 11th and 12th numbers by 2 and 3, respectively. What is the average of the 10th and the 12th numbers? बारह संख्याओं का औसत 55.5 है | पहली चार संख्याओं का औसत 53.4 है तथा अगली चार संख्याओं का औसत 54.6 है | 10वीं संख्या 9वीं संख्या से 3 अधिक है लेकिन 11वीं और 12वीं संख्याओं से क्रमशः 2 और 3 कम है | 10वीं और 12वीं संख्याओं का औसत ज्ञात करें |

Median of a distribution is the value of the variable which divides it into equal parts . In case of individual observations x_1,x_2 .. x_n , if the number of observations is odd, then median is the value of ((n+1)/2) th observation when the observations have been arranged in ascending or descending order of magnitude. In case of even number of observations median is the A.M. of the values of (n/2) th and (n/2+1) th observations, arranged in ascending or descending order of magnitude . The mode of distribution is that value of the variable for which the frequency is maximum . Median of the distribution 25,20,11,3,12,18,17 ,9,21,22 is

Read the passage given below and answer the question: In the last 10 years much has been learned about the molecular structure of elemental sulfur. It is now known that many different types of rings are sufficiently metastable to exist at room temperature for several days. It is known that at high temperature, the equilibrium composition allows for a variety of rings and chains to exist in comparable concentration, and it is known that at the boiling point and above, the vapor as well as the liquid contains small species with three, four, and five atoms. The sulfur atom has the same number of valence electrons as oxygen. Thus, sulfur atoms S_2 and S_3 have physical and chemical properties analogous to those of oxygen and ozone. S_2 has a ground state of 38 sigma 3s^2 sigma "*"3s^2 sigma 3pz^2 pi 3px^2=pi3py^2 pi"*"3px^1=pi"*"3py^1.S3 , thiozone has a well- known uv spectrum, and has a bent structure, analogous to its isovalent molecules O_3, SO_2 , and S_2O . The chemistry of the two elements, sulphur and oxygen, differs because sulfur has a pronounced tendency for catenation. The most frequently quoted explanation is based on the electron structure of the atom. Sulfur has low-lying unoccupied 3d orbitals, and it is widely believed that the 4s and 3d orbitals of sulfur participate in bonding in a manner similar to the participation of 2s and 2p orbitals in carbon. (source: Meyer, B. (1976). Elemental sulfur. Chemical Reviews, 76(3), 367-388. doi:10. 1021//cr603010003 ) In the following question, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the choices on the basis of the above passage. Assertion: S2 is paramagnetic in nature Reason: The electrons in pi"*"3px and pi"*"3py orbitals in S_2 are unpaired.