MPSC PYQ
Science & Technology

Isotopes

Isotopes is a Science & Technology concept from the MPSC syllabus, tested in 11 past MPSC questions across 9 exam years between 2013 and 2025. Below are those real questions with their correct answers and explanations, plus the concepts worth being comfortable with first.

Real questions
11
Years tested
9 · 2013–2025
In context
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Asked in

202520242022202020192017201620142013

What you need to know first

Definition of isotopesDefinition of atomic numberProtons and neutronsAtomic structureHalf-life of isotopesBasic atomic structureIsotopes of carbonNeutrons and ProtonsIsotopes definitionMass number and atomic number

What mastering this unlocks

Radiocarbon datingCarbon-14 half-lifeRadioactivityAlpha decay

Real questions that test this

'अ' गटातील घटकांना 'ब' गटात एकापेक्षा जास्त बरोबर पर्याय उपलब्ध असू शकतात. 'अ' गट 'ब' गट I. 10 इलेक्ट्रॉन्स अ. ²⁰₁₀Ne II. 12 प्रोटॉन्स ब. ²³₁₁Na⁺ III. 12 न्युट्रॉन्स क. ¹⁹₉F⁻ IV. 10 न्युट्रॉन्स ड. ²⁴₁₂Mg²⁺ You may have more than one correct match in Group 'B' for each item in Group 'A'. Group A Group B I. 10 electrons a. ²⁰₁₀Ne II. 12 protons b. ²³₁₁Na⁺ III. 12 neutrons c. ¹⁹₉F⁻ IV. 10 neutrons d. ²⁴₁₂Mg²⁺

1)I - a; II - d; III - b, d; IV - a, c
2)I - a, c; II - d; III - b, d; IV - a
3)I - a, b, c, d; II - d; III - b, d; IV - a, c✓ Correct
4)I - a, b, d; II - d; III - b; IV - a, b, c

Detailed electron, proton, and neutron calculations for Ne, Na+, F-, and Mg2+ match multiple criteria across the groups due to isoelectronic and isotopic relationships.

Carbon compounds are broadly classified into two main categories : 1. Organic compounds : These contain carbon and hydrogen and may also include other elements like oxygen, nitrogen, sulfur etc. They include hydrocarbons (such as methane, ethane, propane), alcohols, acids and polymers (like plastics, rubber). Organic compounds are essential in biological systems, forming the basis of molecules like proteins, carbohydrates, lipids and nucleic acids (DNA and RNA). They are also used widely in industries for example, in the manufacture of fuels, dyes, medicines, pesticides and plastics. 2. Inorganic compounds : These include compounds like Carbon dioxide (CO2), Carbon Monoxide (CO), carbonates (such as calcium carbonate in limestone) and bicarbonates. These compounds are vital in geological and environmental processes, such as the carbon cycle, which maintains the balance of carbon in the eco-system. Carbon compounds exhibit various properties, most organic compounds have low melting and boiling points, are generally flammable and more soluble in organic solvents rather than water. This makes them useful as fuels and industrial solvents. Their diversity and reactivity make them a central part of the field of chemistry, particularly in synthetic and pharmaceutical industries.

कार्बनचा अणुक्रमांक किती आहे ? What is the atomic number of carbon ?

1)04
2)06✓ Correct
3)08
4)12

Carbon is a chemical element with the symbol C and atomic number 6, meaning it has 6 protons in its nucleus.

ऑक्सीजन निसर्गात किती आइसोटोप्स मध्ये आढळतो? / Oxygen occurs in nature in ________ isotopic forms.

1)2
2)3✓ Correct
3)4
4)1

Oxygen occurs naturally in three stable isotopic forms: Oxygen-16, Oxygen-17, and Oxygen-18.

पुढील दोन विधानांपैकी कोणते अयोग्य आहे ? अ. अणु अंक म्हणजे अणु केंद्रातील एकूण प्रोटॉन्सची संख्या. ब. अणु वस्तुमान म्हणजे अणु केंद्रातील एकूण प्रोटॉन्स व न्यूट्रॉन्सची संख्या. Which one of the following statements is/are incorrect ? a. The number of protons in a nucleus is called its atomic number. b. The total number of protons and neutrons constitute its mass number.

(a)अणु अंक म्हणजे अणु केंद्रातील एकूण प्रोटॉन्सची संख्या. / The number of protons in a nucleus is called its atomic number.

(b)अणु वस्तुमान म्हणजे अणु केंद्रातील एकूण प्रोटॉन्स व न्यूट्रॉन्सची संख्या. / The total number of protons and neutrons constitute its mass number.

1)फक्त अ / Only a
2)फक्त ब / Only b
3)दोनों अ आणि ब / Both a and b
4)दोनों नाहीहत / Neither a nor b✓ Correct

Atomic number is indeed defined as the number of protons in the nucleus, and mass number is the sum of protons and neutrons. Both statements are correct, meaning none is incorrect.

ज्या केंद्रभागांचे अणुक्रमांक आणि अणु वस्तुमान विविध असतात, पण न्यूट्रॉनची संख्या समान असेल, तर त्यांना ________ म्हणतात. If nuclides have different atomic numbers and different atomic masses but the same number of neutrons, then they are known as

1)Isotopes
2)Isobars
3)Isotones✓ Correct
4)None of the above

Nuclides with different atomic numbers and mass numbers but the exact same number of neutrons are known as Isotones.

More Science & Technology concepts

ChemistrySound wavesTaxonomyAtomic numberAvogadro numberBiodiversityBiologyMolar massMole conceptPlant morphologyPlant PathologyPollination
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