list all the exceptions in D and f block chapter in class 12 ncert for neet.
D block elements are called as transition elements. F block elements are called as inner transition metals. F block elements were actually a part of group 3 only but due to some similarities in their properties they got a different space in f block table.
Kindly refer to the link below for knowing more about these elements.
Best wishes. Thank-you.
in inorganic chemistry mostly questions are with signs > and even if doing periodic table with exceptions and all my mcqs are getting incorrect leading negative marking!Any solution?
Hi,
You need to do the following to prepare for inorganic:
- Make a list of all the exception of a particular block elements ( suppose d block).
- Put that list up on the front wall of your study table.
- Watch them daily. No need to read. Just watch them in a regular basis.
- Find out problems ( that's going to a tideous job indeed) related to those exception and solve them. Don't forget to take help from your prepared list while solving problems.
You will soon be a master of inorganic. Don't leave inorganic problems in NEET. Inorganic is a highly scoring subject. You just need to practice a lot of questions to grasp all the information of inorganic.
Best of luck ! I believe you will try your best.
list all the exceptions in the periodic table chapter of class 11 ncert.
Hello Aspirant,
Variation in ionisation enthalpies: Ionisation enthalpy increases with increases in atomic number along the period. Some elements show irregularities in this trend due to type of electron to be removed and the extra stability of the exactly half-filled and completely filled electronic configurations.
Variation along the period: In the second period Li to Be, the ionisation enthalpy increases due to increased nuclear charge and smaller atomic radius of Be as compared that of Li. For Be to B, although the nuclear charge of B is more than that of be, yet the ionisation enthalpy of B is lower than that of Be. For B to C to N, the first ionisation enthalpy of these elements keeps on increasing due to progressively increasing nuclear charge and decreasing atomic radius. For N to O, the first ionisation enthalpy of oxygen is lower than that of N although the nuclear charge of O is higher than that of nitrogen. For O to F to Ne, the first ionisation enthalpy increases from O to F to Ne because of the increasing nuclear charge.
Similar variations in the first ionisation enthalpies of the elements of the third period have been observed.
Variation of electron gain enthalpy in a group: In general, the electron gain enthalpies become less negative as we move down a group. But the electron gain enthalpies of some of the elements of second period that is O, and F are however, less negative than the corresponding elements that is s and Cl of the third period.
Thus the electron gain enthalpy of F is unexpectedly less negative than that of Cl.
Also the electron gain enthalpy of noble gases is positive as atoms of these elements have completely filled subshells.
Variation in atomic radii: The atomic radius abruptly increases as we move from halogen (F) to the inert gas (Ne). This is due to the reason that in case of inert gases all the orbitals are completely filled and hence the electronic repulsions are maximum.
Variation of valence in a period: As we move across a period from left to right, the number of valence electrons increases from left to right, the number of valence electrons increases from 1 to 8. But the valence of elements with respect to H or O first increases from 1 to 4 and then decreases to zero.
Electronegativity
This is the easiest of the exceptions. We have said that electronegativity increases to the right. This is true except that the trend does NOT include the noble gases. That means that fluorine has the highest electronegativity, not Ne or He. This is because the definition of electronegativity contains the phrases "in a covalent bond." Since the noble gases don't bond, they don't have electronegativities.
It should be noted that a few of the noble gases have been forced to bond (at high temperture and high pressure with fluorine). You may find tables that, therefore, list values for the electronegativity of Xe and Kr, but these are not terribly important values to know.
Hope this helps,
All the best and thank you!
what is basic consepter and about this
Hello student,
Actually class 11th chemistry is quite easy than twelfth. At first some chapters likes toy Stoichimety, equilibrium and periodic classification are just revision of your 10th level. Then camisan theoretical part like chemical bonding equilibrium thermodynamics. Also there organic chemistry topics like alkanes alkene alkyne. Some blocks like p block d block elements are there in inorganic part you just have to memorize this well .Hope this will help