Advertisements
Advertisements
प्रश्न
Answer the following question:
Which element of the first transition series has highest third ionisation enthalpy?
Advertisements
उत्तर
Among the elements of first transition series zinc has the highest third ionisation enthalpy. Electronic configuration of zinc is: \[\ce{3d^10 4s^2}\]
After the loss of two electrons from 4s orbital, Z and +2 Ion acquires \[\ce{3d^10}\] fully filled configuration which is highly stable therefore removal of third electron from \[\ce{3d^10}\] orbital will be more difficult and requires a large amount of energy.
APPEARS IN
संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called _______.
(A) Duralumin
(B) Babbitt metal
(C) Spiegeleisen
(D) Amalgam
The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why transition elements form alloys.
Maximum magnetic moment is shown by ____________.
Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid-state?
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | An element which can show +8 oxidation state | (a) \[\ce{Mn}\] |
| (ii) | 3d block element that can show | (b) \[\ce{Cr}\] |
| upto +7 oxidation state | (c) \[\ce{Os}\] | |
| (iii) | 3d block element with highest melting point | (d) \[\ce{Fe}\] |
Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.
Read the passage given below and answer the following question.
|
Are there nuclear reactions going on in our bodies? There are nuclear reactions constantly occurring in our bodies, but there are very few of them compared to the chemical reactions, and they do not affect our bodies much. All of the physical processes that take place to keep a human body running are chemical processes. Nuclear reactions can lead to chemical damage, which the body may notice and try to fix. The nuclear reaction occurring in our bodies is radioactive decay. This is the change of a less stable nucleus to a more stable nucleus. Every atom has either a stable nucleus or an unstable nucleus, depending on how big it is and on the ratio of protons to neutrons. The ratio of neutrons to protons in a stable nucleus is thus around 1 : 1 for small nuclei (Z < 20). Nuclei with too many neutrons, too few neutrons, or that are simply too big are unstable. They eventually transform to a stable form through radioactive decay. Wherever there are atoms with unstable nuclei (radioactive atoms), there are nuclear reactions occurring naturally. The interesting thing is that there are small amounts of radioactive atoms everywhere: in your chair, in the ground, in the food you eat, and yes, in your body. The most common natural radioactive isotopes in humans are carbon-14 and potassium-40. Chemically, these isotopes behave exactly like stable carbon and potassium. For this reason, the body uses carbon-14 and potassium-40 just like it does normal carbon and potassium; building them into the different parts of the cells, without knowing that they are radioactive. In time, carbon-14 atoms decay to stable nitrogen atoms and potassium-40 atoms decay to stable calcium atoms. Chemicals in the body that relied on having a carbon-14 atom or potassium-40 atom in a certain spot will suddenly have a nitrogen or calcium atom. Such a change damages the chemical. Normally, such changes are so rare, that the body can repair the damage or filter away the damaged chemicals. The natural occurrence of carbon-14 decay in the body is the core principle behind carbon dating. As long as a person is alive and still eating, every carbon-14 atom that decays into a nitrogen atom is replaced on average with a new carbon-14 atom. But once a person dies, he stops replacing the decaying carbon-14 atoms. Slowly the carbon-14 atoms decay to nitrogen without being replaced, so that there is less and less carbon-14 in a dead body. The rate at which carbon-14 decays is constant and follows first order kinetics. It has a half-life of nearly 6000 years, so by measuring the relative amount of carbon-14 in a bone, archeologists can calculate when the person died. All living organisms consume carbon, so carbon dating can be used to date any living organism, and any object made from a living organism. Bones, wood, leather, and even paper can be accurately dated, as long as they first existed within the last 60,000 years. This is all because of the fact that nuclear reactions naturally occur in living organisms. |
Researchers have uncovered the youngest known dinosaur bone, dating around 65 million years ago. How was the age of this fossil estimated?
Which of the following statements is not correct?
The basic character of transition metals monoxide follow the order.
Agcl is soluble in NH4OH. The solubility is due to the information of:-
A complex in which dsp2 hybridisation takes place is ______.
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
