Alpha Decay

Q.

2 mole of zinc is dissolved in HCl at ${25}^{\circ }C$. The work done in open vessel is:

1. - 2.447 kJ

2. - 4.955 kJ

3. R/2

4. 3R

Q. 40. Wavelength of radiations emitted when an electron jumps from state A to C is 3000 Armstrong and it is 6000 Armstrong when it jumps from B to C. Wavelength of radiations emitted when electron jumps from A to B will be

Q. The wavelength of radiation emitted , when in He+ electron falls from infinity to stationary state would be ________.

Q. if tritium being radioactive emit low energy beta particles then why its atomic no woudnt increase

Q.

Calculate the number of atoms in each of the following:

$16\mathrm{moles}\mathrm{of}\mathrm{He}$

Q. 31. What is the difference between ground state and excited state of ion

Q.

The sum of number of neutrons and protons in tritium is:

1. 4

2. 3

3. 6

4. 5

Q. Which of the following particles is used to bombard ${}_{13}{Al}^{28}$ to give ${}_{15}{P}^{31}$ and a neutron?

1. Deuterium
2. Neutron
3. $\alpha$ - particle
4. $\beta$ - particle

Q. 44 The wavelength of radiation emitted when in He+ electron falls from infinity to stationary state would be ??

Q.

Calculate the number of α- and β-particles emitted when ${}_{92}{U}^{238}$ changes into radioactive ${}_{82}P{b}^{206}.$
(IIT-JEE, 2000)

1. 3, 4
2. 6, 8
3. 4, 3
4. 8, 6

Q.

Thorium with atomic number 92 and mass number 238 disintegrates to give Pb with atomic number 82 and mass number 206. How many alpha and beta particles are emitted during this process?

1. 7 and 8

2. 6 and 7

3. 7 and 6

4. 9 and 6

Q. 201024. In an experiment, 4 g of M2O, oxide was reduced to2.8 g of the metal. If the atomic mass of the metal is56 g mol-, the number of O atoms in the oxide i(a) 1(c) 3(b) 2(d) 4(AFMC)

Q.

In order to form an element Q, an element P disintegrates by $\alpha$-emission and the new element suffers two further disintegrations, both by $\beta$-emission. Explain the fact that the elements P and Q are isotopes.

Q. What is the difference between atomic mass and relative atomic mass

Q. The $\alpha$-particle is identical with

1. Helium nucleus
2. Hydrogen nucleus
3. Electron
4. Proton

Q. A fresh radioactive mixture has short lived species $A$ and $B$. Both emit $\alpha$ − particles initially at 8000 particles per minute. 20 minutes later, they emit 3500 $\alpha$ − particles per minute. If the half – lives of the species $A$ and $B$ are 10 minutes and 500 hours respectively, then the ratio of activities of A : B in the initial mixture was:

1. $4:6$
2. $6:4$
3. $3:4$
4. $3:1$

Q. The wavelength of radiation emitted , when in He+ electron falls from infinity to stationary state would be ________.

Q.

The nucleus ${}_{84}{}^{}\mathrm{X}^{202}$ emits an $\mathrm{\alpha }$-particle and forms the nucleus $Y$. Represents this change in the form of an equation.

Q. number of neutrons present in 8 g atoms of oxygen

Q. In an alpha decay the atomic number of an element decreases by ___.

Q. The Energy of an excited H-atom is -3.4 eV. Calculate angular momentum of e^-.

Q. Consider the nuclear changes.

${}_{82}^{204}Pb\underset{\text{Positron emission}}{\overset{-{\beta }^{+}}{\to }}A\stackrel{-\alpha }{\to }B\underset{\text{Positron emission}}{\overset{-{\beta }^{+}}{\to }}C$

Which of the following statement(s) is/are correct?

1. C is an isotone of ${}_{82}^{204}Pb$
2. A is an isobar of ${}_{82}^{204}Pb$
   
3. C is an isotope of A
4. B is an isobar of C

Q. Consider the nuclear changes.

${}_{82}^{204}Pb\underset{\text{Positron emission}}{\overset{-{\beta }^{+}}{\to }}A\stackrel{-\alpha }{\to }B\underset{\text{Positron emission}}{\overset{-{\beta }^{+}}{\to }}C$

Which of the following statement(s) is/are correct?

1. C is an isotone of ${}_{82}^{204}Pb$
2. A is an isobar of ${}_{82}^{204}Pb$
   
3. C is an isotope of A
4. B is an isobar of C

Q.

U with atomic number 92 and mass number 238 is radioactive and it emits alpha and beta particles to form Pb with atomic number 82 and mass number 206. Calculate the number of alpha and beta particles emitted in this conversation.

An ore of U with atomic number 92 and mass number 238 is found to contain U and Pb in the weight ratio of 1:0.1. The half-life period of U is $4.5\times {10}^9$ years. Calculate the age of the ore.

1. $6.7\times {10}^9$

2. $7.12\times {10}^8$

3. $8.5\times {10}^{10}$

4. $6.6\times {10}^9$