307119
Which of the following are isoelectronic species? \(\underset{\text { (I) }}{\mathrm{CH}_{3}^{+}}, \underset{\text { (II) }}{\mathrm{NH}_{2}^{-}}, \underset{\text { (III) }}{\mathrm{NH}_{4}^{+}}, \underset{\text { (IV) }}{\mathrm{NH}_{3}}\)
1 I, II and III
2 II, III and IV
3 I, II and IV
4 I and II
Explanation:
Isoelectronic means species with same no. of electrons. \(\mathrm{CH}_{3}^{+} \rightarrow 6+3-1=8 \mathrm{e}^{-}\) \(\mathrm{NH}_{2}^{-} \rightarrow 7+2+1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{4}^{+} \rightarrow 7+4-1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{3} \rightarrow 7+3=10 \mathrm{e}^{-}\) So, \(\mathrm{NH}_{2}^{-}, \mathrm{NH}_{4}^{+}\)and \(\mathrm{NH}_{3}\) are isoelectronic species.
CHXI02:STRUCTURE OF ATOM
307120
Assertion : The nuclear isomers are the atoms with the same atomic number and same mass number, but with different radioactive properties. Reason : The nucleus in the excited state will evidently have a different half-life as compared to that in the ground state.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Nuclear isomerism arises from differing energy states in nuclei with the same mass and atomic numbers, resulting in distinct radioactive properties and unique half-lives between ground and excited states. So option (1) is correct.
CHXI02:STRUCTURE OF ATOM
307121
Assertion : Isotopes are electrically neutral. Reason : Isotopes are species with same mass number but different atomic number.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Isotopes of an element share the same atomic number but differ in mass number due to varying neutron counts in the nucleus. Despite this, isotopes remain electrically neutral with an equal number of protons and electrons. So option (3) is correct.
CHXI02:STRUCTURE OF ATOM
307122
If two atoms have equal number of electrons, it is called
1 isoelectronic
2 isobar
3 isotone
4 None of these
Explanation:
The species having same number of electrons are called isoelectronic. For example, \(\mathrm{Na}^{+}\)and \(\mathrm{Mg}^{2+}\) have 10 electrons thus are isoelectronic.
307119
Which of the following are isoelectronic species? \(\underset{\text { (I) }}{\mathrm{CH}_{3}^{+}}, \underset{\text { (II) }}{\mathrm{NH}_{2}^{-}}, \underset{\text { (III) }}{\mathrm{NH}_{4}^{+}}, \underset{\text { (IV) }}{\mathrm{NH}_{3}}\)
1 I, II and III
2 II, III and IV
3 I, II and IV
4 I and II
Explanation:
Isoelectronic means species with same no. of electrons. \(\mathrm{CH}_{3}^{+} \rightarrow 6+3-1=8 \mathrm{e}^{-}\) \(\mathrm{NH}_{2}^{-} \rightarrow 7+2+1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{4}^{+} \rightarrow 7+4-1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{3} \rightarrow 7+3=10 \mathrm{e}^{-}\) So, \(\mathrm{NH}_{2}^{-}, \mathrm{NH}_{4}^{+}\)and \(\mathrm{NH}_{3}\) are isoelectronic species.
CHXI02:STRUCTURE OF ATOM
307120
Assertion : The nuclear isomers are the atoms with the same atomic number and same mass number, but with different radioactive properties. Reason : The nucleus in the excited state will evidently have a different half-life as compared to that in the ground state.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Nuclear isomerism arises from differing energy states in nuclei with the same mass and atomic numbers, resulting in distinct radioactive properties and unique half-lives between ground and excited states. So option (1) is correct.
CHXI02:STRUCTURE OF ATOM
307121
Assertion : Isotopes are electrically neutral. Reason : Isotopes are species with same mass number but different atomic number.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Isotopes of an element share the same atomic number but differ in mass number due to varying neutron counts in the nucleus. Despite this, isotopes remain electrically neutral with an equal number of protons and electrons. So option (3) is correct.
CHXI02:STRUCTURE OF ATOM
307122
If two atoms have equal number of electrons, it is called
1 isoelectronic
2 isobar
3 isotone
4 None of these
Explanation:
The species having same number of electrons are called isoelectronic. For example, \(\mathrm{Na}^{+}\)and \(\mathrm{Mg}^{2+}\) have 10 electrons thus are isoelectronic.
307119
Which of the following are isoelectronic species? \(\underset{\text { (I) }}{\mathrm{CH}_{3}^{+}}, \underset{\text { (II) }}{\mathrm{NH}_{2}^{-}}, \underset{\text { (III) }}{\mathrm{NH}_{4}^{+}}, \underset{\text { (IV) }}{\mathrm{NH}_{3}}\)
1 I, II and III
2 II, III and IV
3 I, II and IV
4 I and II
Explanation:
Isoelectronic means species with same no. of electrons. \(\mathrm{CH}_{3}^{+} \rightarrow 6+3-1=8 \mathrm{e}^{-}\) \(\mathrm{NH}_{2}^{-} \rightarrow 7+2+1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{4}^{+} \rightarrow 7+4-1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{3} \rightarrow 7+3=10 \mathrm{e}^{-}\) So, \(\mathrm{NH}_{2}^{-}, \mathrm{NH}_{4}^{+}\)and \(\mathrm{NH}_{3}\) are isoelectronic species.
CHXI02:STRUCTURE OF ATOM
307120
Assertion : The nuclear isomers are the atoms with the same atomic number and same mass number, but with different radioactive properties. Reason : The nucleus in the excited state will evidently have a different half-life as compared to that in the ground state.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Nuclear isomerism arises from differing energy states in nuclei with the same mass and atomic numbers, resulting in distinct radioactive properties and unique half-lives between ground and excited states. So option (1) is correct.
CHXI02:STRUCTURE OF ATOM
307121
Assertion : Isotopes are electrically neutral. Reason : Isotopes are species with same mass number but different atomic number.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Isotopes of an element share the same atomic number but differ in mass number due to varying neutron counts in the nucleus. Despite this, isotopes remain electrically neutral with an equal number of protons and electrons. So option (3) is correct.
CHXI02:STRUCTURE OF ATOM
307122
If two atoms have equal number of electrons, it is called
1 isoelectronic
2 isobar
3 isotone
4 None of these
Explanation:
The species having same number of electrons are called isoelectronic. For example, \(\mathrm{Na}^{+}\)and \(\mathrm{Mg}^{2+}\) have 10 electrons thus are isoelectronic.
307119
Which of the following are isoelectronic species? \(\underset{\text { (I) }}{\mathrm{CH}_{3}^{+}}, \underset{\text { (II) }}{\mathrm{NH}_{2}^{-}}, \underset{\text { (III) }}{\mathrm{NH}_{4}^{+}}, \underset{\text { (IV) }}{\mathrm{NH}_{3}}\)
1 I, II and III
2 II, III and IV
3 I, II and IV
4 I and II
Explanation:
Isoelectronic means species with same no. of electrons. \(\mathrm{CH}_{3}^{+} \rightarrow 6+3-1=8 \mathrm{e}^{-}\) \(\mathrm{NH}_{2}^{-} \rightarrow 7+2+1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{4}^{+} \rightarrow 7+4-1=10 \mathrm{e}^{-}\) \(\mathrm{NH}_{3} \rightarrow 7+3=10 \mathrm{e}^{-}\) So, \(\mathrm{NH}_{2}^{-}, \mathrm{NH}_{4}^{+}\)and \(\mathrm{NH}_{3}\) are isoelectronic species.
CHXI02:STRUCTURE OF ATOM
307120
Assertion : The nuclear isomers are the atoms with the same atomic number and same mass number, but with different radioactive properties. Reason : The nucleus in the excited state will evidently have a different half-life as compared to that in the ground state.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Nuclear isomerism arises from differing energy states in nuclei with the same mass and atomic numbers, resulting in distinct radioactive properties and unique half-lives between ground and excited states. So option (1) is correct.
CHXI02:STRUCTURE OF ATOM
307121
Assertion : Isotopes are electrically neutral. Reason : Isotopes are species with same mass number but different atomic number.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Isotopes of an element share the same atomic number but differ in mass number due to varying neutron counts in the nucleus. Despite this, isotopes remain electrically neutral with an equal number of protons and electrons. So option (3) is correct.
CHXI02:STRUCTURE OF ATOM
307122
If two atoms have equal number of electrons, it is called
1 isoelectronic
2 isobar
3 isotone
4 None of these
Explanation:
The species having same number of electrons are called isoelectronic. For example, \(\mathrm{Na}^{+}\)and \(\mathrm{Mg}^{2+}\) have 10 electrons thus are isoelectronic.
