National Science Olympiad Forum By SOF Olympiad Trainer - Page 419
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Arnav kaul from Chirec, Hyderabad
Subject :NSO    Class : Class 5

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Harjot Singh from GIIS KL, Kuala Lumpur
Subject :NSO    Class : Class 5

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Tarun from Narayana school, Chennai
Subject :NSO    Class : Class 8

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Divit Rustogi from Apeejay School, Noida
Subject :NSO    Class : Class 3

Ans 1:

SAMRIDDHA PANDA from ST. MONFORT'S SENIOR SECONDARY SCHOOL, BARUIPUR
Class : Class 7
it is sure sure B

Ans 2:

Arpit Sahoo from SAI International School, Bhubaneswar
Class : Class 7
B

Ans 3:

FAIZA AMIN from SAINT XAINS INTERNATIONAL SCHOOL ANANTNAG, ANANTNAG
Class : Class 3
B

Ans 4:

ANSHUL GAJJAR from PODAR INTERNATIONAL SCHOOL, AHMEDABAD
Class : Class 3
B

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Divit Rustogi from Apeejay School, Noida
Subject :NSO    Class : Class 3

Ans 1:

SAMRIDDHA PANDA from ST. MONFORT'S SENIOR SECONDARY SCHOOL, BARUIPUR
Class : Class 7
ans:D

Ans 2:

Darshini Chakravarty from Pinnacle High International School, Mumbai
Class : Class 4
ans is d

Ans 3:

SAMRIDDHA PANDA from ST. MONFORT'S SENIOR SECONDARY SCHOOL, BARUIPUR
Class : Class 7
ans:D

Ans 4:

Manvik Sai from Edify, Kurnool
Class : Class 3
D

Ans 5:

Arpit Sahoo from SAI International School, Bhubaneswar
Class : Class 7
D non of these

Ans 6:

FAIZA AMIN from SAINT XAINS INTERNATIONAL SCHOOL ANANTNAG, ANANTNAG
Class : Class 3
C

Ans 7:

Meghatyoya from Adamas World School , Barasat
Class : Class 3
how??

Ans 8:

saisavit from sri kumaran ps, bangalore
Class : Class 7
Why answer is not D.

Ans 9:

SAMRIDDHA PANDA from ST. MONFORT'S SENIOR SECONDARY SCHOOL, BARUIPUR
Class : Class 7
ans:D

Ans 10:

Atri Pradhan from Oxebow English School, Gobardanga
Class : Class 3
none of these

Ans 11:

ANSHUL GAJJAR from PODAR INTERNATIONAL SCHOOL, AHMEDABAD
Class : Class 3
D

Ans 12:

Atri Pradhan from Oxebow English School, Gobardanga
Class : Class 3
d

Ans 13:

Kanishk gupta from Prime academy, Mumbai
Class : Class 4
wtf

Ans 14:

ANSHUL GAJJAR from PODAR INTERNATIONAL SCHOOL, AHMEDABAD
Class : Class 3
D

Ans 15:

Arjun Gourineni from CHIREC International School, Hyderabad
Class : Class 7
D

Ans 16:

Kanishk gupta from Prime academy, Mumbai
Class : Class 4
d

Ans 17:

SAMRIDDHA PANDA from ST. MONFORT'S SENIOR SECONDARY SCHOOL, BARUIPUR
Class : Class 7
ans:D

Ans 18:

Vaishnavi Harish Iyer from Vikhe Patil Memorial School, Pune
Class : Class 8

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svayumbhu sharma from jodhamal public school, jammu
Subject :NSO    Class : Class 8

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Shailja from The Pentecostal assembly school, Bokaro
Subject :NSO    Class : Class 8

While demonstrating the reactivity order of different metals, a science teacher arranged the following apparatus :

Select the correct statement regarding this activity.

A A chemical change will take place in all the three beakers if metal Y is magnesium.
B There will be no change in colour of solution if metal Y is aluminium.
C The reactivity order of given metals is Y > Zinc > Iron > Copper if reaction occurs in beaker (III).
D All of these


Ans 1:

Amol Athawale from WoodRidge High, aurangabad
Class : Class 6

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Aarush from Podar, Mumbai
Subject :NSO    Class : Class 6

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Agastya Tripathi from dps gurgaon, Gurgaon
Subject :NSO    Class : Class 5

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Pragun goel from Venkateshwar International School, Delhi
Subject :NSO    Class : Class 5

Ans 1:

Bhavya from ABC, Delhi
Class : Class 7
the order should be 1-3-2 . there is no option like that. what are these SOF people

Ans 2:

Katelyn Asir from Kendriya Vidyalaya, Chennai
Class : Class 5
The correct option should be - 1-3-2 ( Sedimentation - Filtration - Chlorination )This option is not given. Sedimentation - All the particles settle down as gravity pulls the heavier sediments down.Filtration - It removes the sediments from the water.Chlorination - Process of adding chlorine to water and removing the parasites,bacteria and viruses. Now the water is purified.

Ans 3:

samanvay sinha from School of India, Bangalore, bengaluru
Class : Class 5
please no printing errors

Ans 4:

Srija Das from Sent Joseph Convent Chandannagar, Serampore
Class : Class 9

Ans 5:

niuv from meridian, Hyderabad
Class : Class 6

Ans 6:

Suresh Gyanchandani from St. Anselms Pink City Senior Secondary School, Jaipur
Class : Class 5
Correct option should be 1, 3, 2.

Ans 7:

Hari Govind from Delhi Public School Chandigarh , Chandigarh
Class : Class 6
1-3-2 is the correct order as first we should remove all the insoluble impurities and the the soluble impurities.

Ans 8:

Devina kashyap from TPS, Mumbai
Class : Class 4
the correct order is 1,3,2 but there is no option like that but if you look at option A you'll find the correct order in a descending order (from back) so if there is no option like 1,3,2 then A should be correct

Ans 9:

Navya GUPTA from dps noida, Noida
Class : Class 3

Ans 10:

Agastya Tripathi from dps gurgaon, Gurgaon
Class : Class 4

Ans 11:

Navya GUPTA from dps noida, Noida
Class : Class 3

Ans 12:

Mithul Pranav KB from Narayana Olympiad School Madipakkam, Chennai
Class : Class 5
The correct order is 1-3-2 and there is no option like that .So,I think that it might be a printing error.

Ans 13:

VAIBHAV RAI from Cambridge Court High School, JAIPUR
Class : Class 8
The correct order is 1-3-2 but there's no option having it

Ans 14:

Debashree Samanta from DPS BANGALORE , bangalore
Class : Class 5
the order is not 1-2-3. it is 1-3-2. but there is no option

Ans 15:

Swastik Srivastava from Baldwin Boys High School, Bangalore
Class : Class 5
correct order is 1-3-2 but there is no option

Ans 16:

Anshu Manglik from Delhi Public School, Gurgaon
Class : Class 7

Ans 17:

Mithul Pranav KB from Narayana Olympiad School Madipakkam, Chennai
Class : Class 5
(i) Sedimentation - Sedimentation is a physical water purification process using gravity to remove suspended solid impurities from water. The water is allowed to stand till the suspended solid impurities, which are heavier than water, are pulled down by gravity and settle at the bottom of the container.(ii) Chlorination - Chlorination is the process of adding chlorine, or chlorine compounds such as sodium hypochlorite, to drinking water to disinfect it and kill germs. The addition of chlorine will also oxidize any iron, manganese and/or hydrogen sulphide that are present, so that they too can be removed in the filtration process later on.(iii) Filtration - Filtration is a process of water purification, which is used to separate solid impurities from water by using a filter medium that allows the water to pass through but not the solid impurities. These solid impurities are not heavy, so they do not settle at the bottom, but remain suspended. So, a filter is used to trap them.So, to purify water, it must go through sedimentation (i) first, so that heavier and larger size impurities like sand and dirt, are allowed to settle at the bottom of the container and are removed first. Next, water must go through chlorination (ii), so that bacteria and germs present in water are killed. Any iron, manganese and/or hydrogen sulphide, if present, also get oxidized by chlorine. These can be removed later by the filtration (iii) process, along with other suspended impurities.Hence, the right answer is Option D.

Ans 18:

PRANAV VELDURTI from meridian school madhapur, hyderabad
Class : Class 9

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