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Question: 1
From which word atom derived?
Answer: 1
1-39Atom is derived from the Latin word"Atomos' meaning indivisible
Question: 2
What is the nature of charge on cathode rays?
Answer: 2
2-39Their deflection in electric and magnetic field proves that they have negative charge.
Question: 3
Name the particles which determine the mass of an atom?
Answer: 3
3-39Protons and neutrons determine the mass of an atom.
Question: 4
Do you know any element having no neutrons in its atom.
Answer: 4
4-39Isotope of hydrogen, protium have one proton and no neutrons in it.
Question: 5
What was teh thickness of gold foil used in ruther ford's atomic model?
Answer: 5
5-390.00004 cm thick gold foil was used by Rutherford in his experiment
Question: 6
When do electrons emit or absorb energy?
Answer: 6
6-39As long as electron remains in a particular orbit it does not radiate or absorb energy. The energy is emitted or absorbed only when an electron jumps from one orbit to another.
Question: 7
What will be the nature of charge on an atom when it loses an electron or when it gains an electron?
Answer: 7
7-39When it lose an electron it became positive an when it gain and electron it became negative
Question: 8
What are defects of Rutherford's atomic model?
Answer: 8
8-39Following are the defect of Rutherford's atomic model.
According to classical theory, electrons being charged particles should release or emit energy continuously and they should ultimately fall into nucleus.
If electrons emit energy continuously, they should form a continuous spectrum but iin fact, Line spectrum was observed.
Question: 9
Define atome according to Dalton?
Answer: 9
9-39Atom is an indivisible, hard, dense and sphere.
Question: 10
How was the shown that atomic muclei are positively charged?
Answer: 10
10-39The deflection of a few particles proved that there is a center of positive charge in an atom which is called nucleus of an atom.
Question: 11
What is quantum?
Answer: 11
11-39Quantum means fixed energy. It is the smallest amount of energy that can be emitted or absorbed as electromagnetic radiation.
Question: 12
A patient has goiter. How will it be detected?
Answer: 12
12-39The radioactive isotopes are used as tracers in medicine to diagnose the present of a tumor in human body. Isotope of 1-131 is used for diagnosis of goiter in thyroid gland.
Question: 13
Define Isotope?
Answer: 13
13-39"Isotopes are defined as the atoms of elements that have same atomic number but different mass number.
Question: 14
State properties of positive rays ?
Answer: 14
14-391- These rays travel in a straight line in a direction opposite to cathode rays
3- The positive rays produced by using hydrogen gas are known as protonss
Question: 15
What are shells?
Answer: 15
15-39Shells are specific energy levels around nucleus in which electrons revolve. e.g. K, L, M, N.
Question: 16
Write two postulates of Bohar's atomic model.
Answer: 16
16-39The Bohr's atomic model was based upon the followingpostulates
1- Each orbit has a fixed energy that is quantized .
2- The ; hydrogen atom consists of a tiny nucleus and electrons are revolving in one of circular orbits of radius r around the nucleus
Question: 17
Explain"Plum pudding"theory.
Answer: 17
17-39Thomson put forth his 'plum'pudding' theory. He postulated that atoms were colid structure of positively charge with tiny negative particles stuck inside. It is like plums in the pudding.
Question: 18
Who discovered electron, proton and neutron
Answer: 18
18-39In 1886, Goldstein discovered positively chrged particles called protons. In 1897, J.J. Thomson found in an atom, the negatively charged particles known as electrons. In 1932 James Chadwick discovered neutron.
Question: 19
What is the classical theory of radiation? How does it differ from quantum theory?
Answer: 19
19-39Classical Theory:
According to it , electrons being the charged particles should release or emit energy continuously and they should ultimately fall into the nucleus.
Question: 20
A patient has goiter; how will it be detected?
Answer: 20
20-39Isotopes of iodine = 131 are used for diagnosisof goiter in thyroid gland .
Question: 21
What is Dalton's atomic theory?
Answer: 21
21-39According to Dalton.
1. An atom is an indivisible, hard and ense sphere
2. Atoms of same element are alike.
3. Atom combine in different ways to form compounds.
Question: 22
Write use of Co-6o.
Answer: 22
22-39Cobalt-60 emits stronglypenetrating gamma rays and hence used for cancer affecting within the body.
Question: 23
Define nuclear fission reaction?
Answer: 23
23-39A reation in which heavy nuclear splits up into two nuclei by absorbing show moving next ions.
Question: 24
How is the goiter in thyroid gland detected?
Answer: 24
24-39Isotope of Iodine -131 is used for diagnosis of goiter in the thyroid gland.
Question: 25
What is the capacity of shells?
Answer: 25
25-39The number of electrons accommodated by the shell called capacity of shell.
Question: 26
How does electron differ from a neutron?
Answer: 26
26-39Electrons
1- Electron is the negative charged particle.
2- Electron revolves around the nucleus.
3- Mass of electron is 5.486 x 10-4amu
Question: 27
How many sub shells are there in second shells?
Answer: 27
27-39Two shells s and p are present in second shell I.
Question: 28
Write down the isotopes of carbon
Answer: 28
28-39There are two stable isotopes of carbon12C and13C and one radioactive isotope14C
Question: 29
Differentiate between shell and sub shell.
Answer: 29
29-39Shell
1- The shells are sub divided into sub shell.
2- The fixed circular orbits which is associated with a definite amount of energy is called shell .
3- K, L, M,N etc. are considered as shell.
Question: 30
Which carbon isotope use in carbon dating?
Answer: 30
30-39C-14 used in carbon dating.
Question: 31
Why do isotopes of an element have similar chemical properties?
Answer: 31
31-39Isotopes have similar chemical properties because these depend upon electronic configuration and isotopes have same electronic configuration, and number of protons
Question: 32
Write down the electronic configuration of Cl ion.
Answer: 32
32-39Chlorine has atomic number 17 , its electronic confiquration is following
17Cl= 1s2, 2s2, 2p6, 3s2, 3p5
Question: 33
Give one example each of the use of radioactive isotope in medicine and radiotherapy.
Answer: 33
33-39Radioactive isotopes used in medicine.
Iodine 131
Radioactive isotopes used in Radiotherapy
P -32
Sr -90
Co-60
Question: 34
What is meant by Quantum?
Answer: 34
34-39Quantum:
Quantum means fixed energy. It is the smallest amount of energy that can be emitted or absorbed as electromagnetic radiation, Quanta are plural of quantum
Question: 35
How is the goiter is thyroid gland detected?
Answer: 35
35-39Iodine-131 is used for the diagnosis of foiter in thyroid gland.
Question: 36
Define nuclear fission reaction
Answer: 36
36-39Nuclear fission reaction
Nuclear fission is the type of nuclear reaction in which a radioactive element (23592U) is bombarded with slow moving neutrons that23592 U + 10n _________>13956Ba +9436 Kr +310n +energy
Question: 37
Define Electronic configuration?
Answer: 37
37-39"The distribution of electrons around the nucleus in various shells and sub shells according to increasing energy, is called electronic configuration".
Question: 38
State four uses of isotopes .
Answer: 38
38-39Uses of Isotopes:
1- Radiotherapy
2- Tracer for diagnosis and medicine
3- Archaeological and geological uses.
4- Chemical reactionand structure determination
5- Applications in power generation
Question: 39
How the electrons of Na are distributed in different shells?
Answer: 39
39-39The electronic configuration of sodium will be written in shell as
K L M
2 8 1
Further distribution of electrons in sub shells will be : 1s2, 2s2 , 2p6, 3s1
