ICSE PHYSICS ||Class10 || Radioactivity ||Nuclear Fission ||Nuclear Fusion ||Selina Physics ||
ฝัง
- เผยแพร่เมื่อ 7 ธ.ค. 2024
- Instagram: ...
Radioactivity Unit (A)
Part-I : • ICSE PHYSICS || Class ...
PART-II : • ICSE PHYSICS ||Class ...
PART-III : • ICSE PHYSICS ||Class 1...
The three constituents of an atom are electrons, protons and neutrons.
(a) Atomic number (Z) - The atomic number of an atom is equal to the number of protons in it's nucleus (which is same as the number of electrons in a neutral atom). i.e.,
Z = number of protons in the nucleus of an atom.
(b) Mass number (A) - The mass number of an atom is equal to the total number of nucleons (i.e., the sum of the number of protons and the number of neutrons ) in it's nucleus. i.e.,
A = number of protons + number of neutrons in the nucleus of an atom.
The atoms of the same element, having same atomic number Z, but different mass number A, are called isotopes.
The atoms of different elements which have the same mass number A, but different atomic number Z are called isobars.
Radioactivity is a nuclear phenomenon. It is the process of spontaneous emission of α or β and γ radiations from the nucleus of atoms during their decay.
Uranium and Polonium are radioactive substances.
There will be no change in the nature of radioactivity when a radioactive substance is oxidized because radioactivity is a nuclear phenomena.
α and β radiations are charged particles (i.e., α radiation is positively charged and β radiation is negatively charged) therefore, they are deflected in an electric or magnetic field. γ radiations are uncharged particles hence, they do not show deflection in an electric or magnetic field.
‘Radioactivity is a nuclear phenomenon’.GIVE REASON:
Any physical change (such as change in pressure and temperature) or chemical change (such as excessive heating, freezing, action of strong electric and magnetic fields, chemical treatment, oxidation etc.) does not change the rate of decay and the nature of radiation emitted by the substance.
This clearly shows that the phenomenon of radioactivity cannot be due to the orbital electrons which could easily be affected by such changes. Therefore the radioactivity should be the property of the nucleus. Thus, radioactivity is a nuclear phenomenon.
(i) Atomic number
When an α particle is emitted atomic number decreases by 2.
When a β particle is emitted atomic number increases by 1.
When γ radiation is emitted there is no change in atomic number.
(ii) Mass number
When an α particle is emitted mass number decreases by 4.
When a β particle is emitted there is no change in the mass number.
When a γ radiation is emitted there is no change in the mass number.
The isotopes of some elements with atomic number (Z) less than 82 are found to be radio active. They are called the radio isotopes.
State the medical use of radioactivity.
Answer
Many diseases such as leukemia, cancer, etc., are cured by radiation therapy. γ radiations from cobalt-60 are used to treat cancer by killing the cells in the malignant tumor of the patient.
The salt of weak radioactive isotopes such as radio-sodium chloride, radio-iron and radio-iodine are used for diagnosis. Such radio isotopes are called the tracers. These tracers are used to detect the suspected brain tumors and blood clots before they become dangerous.
γ rays emitted by the radio isotopes are used to sterilize bandages, dressings, syringes and other equipments to make them free from germs.
BACKGROUND RADIATIONS:the radioactive radiations (such as α, β and γ) to which we all are exposed, even in the absence of an actual visible radioactive source.
The radioactive substance such as potassium-40
,Carbon-14
and radium are present inside our bodies.
Cosmic rays, the solar radiation coming from out space and naturally accruing radioactive elements such as
and solar radiation are sources of background radiation.
NUCLEAR ENERGY:In a nuclear change due to a radioactive phenomenon (such as decay, fission or fusion), the total sum of masses of product nuclei is always less than the total sum of the masses of reactant nuclei. Thus, there ia a loss of mass, due to which the energy is released. The energy so obtained is called the nuclear energy.
The radioactive phenomenon responsible for the release of nuclear energy are fission and fusion.
What is nuclear fission? Name the substance used for it. Write one fission reaction.
Nuclear fission is the process in which a heavy nucleus splits into two lighter nuclei of nearly the same size, when bombarded with slow neutrons. In each fission reaction, a tremendous amount of energy is released.
Uranium is one substance that can be used for nuclear fission.
Approximately 190 MeV energy is released in the fission of one nucleus.
Nuclear fusion is the process in which two light nuclei combine to form a heavy nucleus. In this process, huge amount of energy is released.
Sir, our text has this chapter named modern physics. I searched for ur classes but i was not able to find it out.. then i understood that,in selina publications,this chapter's name is radioactivity. I heaved a sigh of relief after finding the videos🤗🤗 because I'm adicted to ur classes and whenever i learn physics.. i want ur classes for my life ahead.....For +1,+2,neet. I think ur classes are gonna guide and protect me from huge concepts of physics through ur explanations....❤❤
Thanks in such a wonderful messages dear.
My heart is flying. I got best student.
Definitely dear I will support you in class 11th and 12th....
Hope you subscribed Our New TH-cam Channel
th-cam.com/video/FbJjrMBQXFU/w-d-xo.html
Sir thank you very much. Your video was very helpful for me to learn the chapter thoroughly.
That's really glad to hear dear. Thanks for watching and supporting our channel.if any doubts can mention. Hope you will share our videos with ur frds to support our channel to grow 😊. All the best dear 😊
Sir even say what type of questions will come from this chapter 12 b
Hello dear
Definitely we will do
Thanks for your suggestion 😊
Thank you soooo much sir u r the best!😊
Thanks for watching and supporting our channel.if any doubts can mention. Hope you will share our videos with ur frds to support our channel to grow 😊. All the best dear Regards 😊
Sir could you please make a video of electro-magnetism class10
Hello dear Nitya, already 2 units of electromagnetism were uploaded in our channel. Kindly check the link given below
ELECTROMAGNETISM: th-cam.com/play/PLAaK7Jd_4LuxhBJdk7TlxY_o2sEb113mD.html
What is heavy water
Hello dear...it is Duterium Oxide
Sir please please make the video on" Magnetism "class 9
Hello dear, Definitely will be uploaded soon. Thanks for watching and supporting our channel.if any doubts can mention. Hope you will share our videos with ur frds to support our channel to grow l. All the best dear
sirrrrrrrr gouse hold new video you will upload or can we refer last year video becoz time will waste sir
Hello dear...present you can refer old one...very soon we will upload House hold current ONE SHOT VIDEO
thank you
Sir lots of love from 10 J
So nice of you dear
Sir I think its salman khan movie jai ho
Thanks dear...for information
th-cam.com/video/hawn08j1nOk/w-d-xo.html
It is Our NEW TH-cam CHANNEL started for class11th and 12th JEE MAINS AND NEET. Hope you will SUBSCRIBE and share to support