Question

⇒ వివరణతో సమాధానం ఇవ్వండి :-
⇒ स्पष्टीकरण के साथ उत्तर दें :-
⇒ Answer with Explanation :-
1. The least heaviest of all sub atomic particles is discovered by __
2. The number of protons and electrons present in the Aluminium ion is _____ & ______ respectively.
3. The reason behind the occurrence of isotopes is __
4. If shells are labeled as K, L, M, N, O etc from the nucleus, the maximum number of electrons in O shell are __
5. A neutral atom of an element has 2 electrons in K shell and 1 electron in L shell. Its nucleus consists of 4 neutrons. Then the atomic and mass number of the same are _____ & _____ respectively
6. The number of valence electrons in Chloride ion is __
7. The unit charge of the sub-atomic particle which is discovered last (after the discovery of the first two sub-atomic particles) is __
8. The isotope of this element is used in detection of age of fossils (remains of dead plants and animals) is __
9. A radioactive element ‘X’ consists of 92 protons and 92 electrons. If its mass number is 238, then the number of neutrons in it are __

Answer 1

• The least heaviest of all sub-atomic particles is discovered by J.J Thomson.

The least heaviest sub-atomic particle is electron with mass 9.1093837015×10-³¹was discovered by J.J Thomson.

• The number of protons and electrons present in the Aluminium ion is 13 and 10 respectively.

The Aluminium atom usually has 13 protons and 13 electrons. But the Aluminium ion has 13 protons and 10 electrons to give it +3 charge (-10+13=+3).

• The reason behind the occurrence of isotopes is radioactive decaying of nucleus.

Isotopes can either form naturally through radioactive decay of a nucleus or artificially by bombarding a stable nucleus with charged particles via neutrons in a nuclear reactors.

Isotopes are atoms of same elements having different number of neutrons but same number of protons and electrons.

• If shells are labelled as K, L, M, N , O etc. from the nucleus, the maximum number of electrons in O shell are 50 electrons.

The no.of electrons in a shell is given by 2n²:-

==> K shell = 2(1)² = 2 electrons

==> L shell = 2(2)² =8 electrons

==> M shell = 18 electrons

==> N shell = 32 electrons

==> O shell = 2(5)² = 50 electrons

• A neutral atom of an element has 2 electrons in K shell and 1 electron in L shell. It's nucleus consists of 4 neutrons. Then the atomic and mass number of the same are respectively 3 and 7.

Atomic number = No. of electrons/No.of protons

==> K shell + L shell

==> 3 electrons

Mass number = Protons (Atomic number) + Neutrons

==> 3 + 4

==> 7

• The number of valence electrons in Chlorine ion is 7.

The atomic number of Chlorine is 17 and the electronic configuration is 2,8,7. So, 7 is the number of valence electrons in Chlorine.

• The unit charge of the sub-atomic particle which is discovered last ( after the discovery of the first two sub-atomic particles ) is 0.

After the discovery of electrons and protons, neutrons were discovered whose charge is 0.

• The isotope of this element is used in detection of age of fossils ( remains of dead plants and animals ) is Carbon-14.

Radiocarbon dating ( usually referred as carbon-14 dating ) is used to estimate the age of carbon-bearing materials upto about 58,000 to 62,000 years old.

• A radioactive element 'X' consists of 92 protons and 92 electrons. If it's mass number is 238, then the number of neutrons in it are Uranium.

Uranium has 92 electrons, 92 protons and mass number 238.

Mass number of an atom = Protons + Neutrons

==>238 = 92-Neutrons

==>Neutrons = 146

_____________________

✨ Good night ✨

Answer 2

Explanation:

1. The least heaviest of all subatomic particles was discovered by Sir JJ Thompson , and that subatomic particle is known as electron which has mass of 9.1 × 10^-27 kg / ( 9.1 × 10^-31 g). The electrons are negatively charged.

2. The number of protons and electrons present in the Aluminium ion (Al+3) is 13 and 10 respectively . The number of electrons is less than that of protons as the ion is a cation and is positively charged.

3. The main reason behind the occurence of isotopes is the theory of radioactive decay or the radioactive disintegration.

4. The number of electrons in the O subshell are 50, since 'n' of O subshell is 5 and the number of electrons is given by 2(n)^2

5. The atomic number is given by the total number of protons/electrons , so here we have 3 electrons therefore the atomic number is 3 . The mass number is given by sum of protons and neutrons , and it is (3+4) =7

6. The number of valence electrons in chloride ion (Cl-) is 7

7. The unit charge of the subatomic particle which is discovered last is 0

8. The isotope of Carbon ( carbon-14) is used in detection of age of fossil fuels, and this process is called carbon dating.

9. The radioactive element X is Uranium . The number of neutrons is (238-92) = 146