Chapters

Structure of Atom

An atom cosists of a small positively charged heavy nucleus, with negatively charged plight electrons revolving around the nucleus in circular paths called orbits. Atom is made up of three fundamental particles:

  1. Electron
  2. Proton
  3. Neutron

 

Nutrones and protons are inside the nucleus whereas electrons are found outside the nucleus.

Proton

Proton is a positively charged particle having a charge of +1.6 × 10-19 coulombs. The mass of a proton is about 1836 electrons, the relative mass of a proton is 1 a.m.u(1 atomic mass unit), which is the same as that of a hydrogen atom. The hydrogen atom have the lowest mass.

Electron

Electron is a negatively charged particle having an absolute charge of -1.6 × 10-19 coulombs. A normal atom has an equal number of protons and electrons and since a proton and an electrons and since a proton and an electon have equal and opposite charge, an atom on the whole is electrically neutral.

Neutron

Neutron is an uncharged particle or neutral particle which is present in the nucleus of an atom. The mass of a neutron is the same as that of proton i.e. 1amu. The relative charge of a neutron is zero

Atomic Number

The number of protons present in the nucleus of an atom of an element is called its atomic number. For example, if an element has 2 protons in the nucleus of its atom, then its atomic number is 2.

Mass Number

The total number of protons and neutrons present in the nucleus of one atom of an element is called its mass number.
Mass Number = No. of Protons + No. of Neutrons.

Isotopes

All the atoms of an elements contain the same number of protons but they may have different number of neutrons. The atoms of an element having the same atomic number but different mass numbers are called isotopes.

Radioactivity

The heavy elements like uranium, thorium and radium disintigrate themselves in an uncontrollable manner and emit alpha, beta particles and gamma rays. This phenomenon of disintigration is known as radioactivity.

Chemical Reactions

In a chemical reactions, only the outermost electrons of the atoms takes part, the nuclei of the atoms remain unaffected.

Nuclear Reactions

In nuclear reactions, the nucleus of an atom undergoes a chang forming new atoms and releasing a tremendous amount of energy. New atoms can be produced in a nuclear reaction, which is not possible in the case of a chemical raction. The first ever nuclear reaction was carried out by Tutherford in 1919.

Transuranic Element

The elements above atomic number 92(i.e of uranium) are called as transuranic elements.

Forces insde the Nucleus

It is found that the nuclei of small atoms are quite stable but the nuclei of big atoms are unstable. There are two type of forces operating insde the nucleus of an atom. These are:

  1. Electrostatic Force: The force which a charged particle exerts on another charged particle is called electrostatic force. The electrostatic force may cause attraction or repulsion depending upon the nature of charges of particle. If two particle have opposite charges then the electrostatic force cause attraction between them but they have similar charges then the electrostatic force will be repulsive.
  2. Nuclear Force: TThe force with which two protons, two neutrons or a proton and a neutron attract one another in the nucleus is called nuclear force(Strong force)

 

Nuclear Fission

An atom contains protons and neutrons in its central nucleus. In fission, the nucleus splits, either through radioactive decay or because it has been bombarded by other subatomic particles known as neutrinos. The resulting pieces have less combined mass than the original nucleus, with the missing mass converted into nuclear energy. This process is known as nuclear fission

Nuclear Fusion

In nuclear reaction two or more atomic nuclei come very close and then collide at a very high speed and join to form a new nucleus. During this process, matter is not conserved because some of the matter of the fusing nuclei is converted to photons (energy). This process is known as nuclear Fusion


Latest Current Affaris

Current affairs 05/06/2019
Current affairs 05/06/2019

1). Comptroller and auditor general Rajiv Mehrishi has been appointed as the external auditors of World Health Organisation (WHO) for a four year term from 2020-23. 2).World Environment Day is observed on 5 June(Theme: The Air Pollution). 3). Madhya Pradesh cabinet has passed a resolution to increase reservation of OBC's 27%.

करंट अफेयर्स 03-04/06/2019
करंट अफेयर्स 03-04/06/2019

1. नयब बुकेले को ईआई सल्वाडोर के राष्ट्रपति के रूप में चुना गया है। (ईआई सल्वाडोर की राजधानी: सैन सल्वाडोर, मुद्रा: संयुक्त राज्य अमेरिका डॉलर) 2. राष्ट्रीय सुरक्षा सलाहकार (NSA) अजीत डोभाल की दोबारा अपने पद पर नियुक्ति हुई। NDA सरकार के दूसरे कार्यकाल में उन्हें कैबिनेट रैंक दिया गया है। 3. 3 जून को विश्व साइकिल दिवस मनाया जाता है।

Current affairs 03-04/06/2019
Current affairs 03-04/06/2019

1. Nyaib Bukele has been Sworn in as the president of  EI Salvador ( EI Salvador's capital: San Salvador, currency: United States Dollar). 2. National Security Advisor (NSA) Ajit Doval reappointed to his post and given Cabinet rank in the second term of the NDA government. 3. World Bicycle Day is observed on 3rd June .

Current Affairs Quiz

डेली जीके क्विज 17/05/2019
डेली जीके क्विज 17/05/2019

1. भारतीय नौसेना प्रमुख का नाम बताएं? 2. हाल ही में ICC द्वारा पहली महिला मैच रेफरी के रूप में किसे नियुक्त किया गया है? 3. हाल ही में एक हल्के खेल विमान (एलएसए) में अटलांटिक महासागर को पार करने वाली दुनिया की पहली महिला कौन बनी है?

Daily Gk Quiz 17/05/2019
Daily Gk Quiz 17/05/2019

1. Name the Indian Navy Chief? 2. Recently who has been appointed as first female match referee by ICC? 3. Recently who has becomes the world’s first woman to cross the Atlantic Ocean solo in a light sports aircraft (LSA)?

डेली जीके क्विज 29/09/2018
डेली जीके क्विज 29/09/2018

प्रश्न 1)। हाल ही में एशियाई विकास बैंक (एडीबी) ने राज्य में रोजगार को बढ़ावा देने के लिए मध्य प्रदेश में पहला बहु-कौशल पार्क स्थापित करने के लिए 150 मिलियन डॉलर के ऋण को मंजूरी दे दी है। एडीबी के अध्यक्ष कौन हैं? प्रश्न 2)। परकर्म परव किस अवसर पर मनाया जा रहा है? प्रश्न 3)। भारत की लाइव स्टॉक जनगणना 1 अक्टूबर से शुरू होने वाली है। इस तरह की कितनी जनगणना पहले आयोजित की गई है और यह कौन सी जनगणना है?