Question

Prep Work #4

CHM 1210

MODEL 1: Spontaneous Nuclear Reactions

Type Note: all spontaneous processes form more stable products	Example                            Nuclear Equation (s)
Alpha Radiation (α): A large, unstable nucleus decays to produce a smaller, more stable nucleus and an alpha particle (identical to a helium nucleus, 42He or 42α).	23892U ® 23490Th + 42α
Beta Radiation (β): A neutron in an unstable nucleus decays, forming a proton and emitting a beta (β) particle (identical to an electron, 0-1e or 0-1b) and resulting in a more stable nucleus.	10n ® 11p + 0-1e 146C ® 147N + 0-1e
Gamma Radiation (γ): An unstable nucleus releases energy in the form of a high energy photon (no mass)to become more stable; this often accompanies other forms of radioactivity.	none
Positron Emission (β+): A proton in an unstable nucleus decays, forming a neutron and emitting a positron (β+), (identical to an electron, but positive, 01e or 01b) and resulting in a more stable nucleus.	11p ®10n + 01e 4019K ® 4018Ar + 01e
Electron Capture (EC): A proton in an unstable nucleus absorbs a low energy level electron to form a neutron and to produce a more stable nucleus.	11p + 0-1e ® 10n 19780Hg + 0-1e ® 19779Au

Questions:

What is an alpha particle? What do the numbers 4 and 2 refer in the symbols for the alpha particle? Why is He used sometimes in the symbol for the alpha particle?

What happens to a nucleus when alpha radiation occurs?

What is a beta particle? What do the numbers 0 and -1 refer to in ⁰_-1e? Why is e used as part of the symbol for the beta particle?

What reaction is happening inside the nucleus of an atom when beta radiation occurs?

What is the symbol for gamma radiation? What do the two zeros to refer in ⁰₀γ? What is gamma radiation? What happens to the nucleus of an atom when it occurs?

To what do the numbers 0 and 1 refer in the positron symbol? Why is e used as part of the positron symbol? What reaction is happening inside the nucleus of an atom when positron radiation occurs?

What do all five type of spontaneous nuclear reactions have in common?

Model 2. Balancing Nuclear Equations

Nuclear Equation (s)
23892U ® 23490Th + 42α	10n + 23592U ® 14256Ba + 9136Kr + 310n + 00γ
10n ® 11p + 0-1e	23894Pu ® 23492U + 42He
146C ® 147N + 0-1e	2 21H ® 32He + 10n + 00γ
11p ®10n + 01e	11p + 0-1e ® 10n
4019K ® 4018Ar + 01e	42He + 94Be ® 126C + 10n + 00γ
19780Hg + 0-1e ® 19779Au

Key Questions

Look at the example equation for alpha radiation (top left equation). What is balanced about this equation?

Are the other nuclear equations on the page balanced in this same way?

A10.Polonium-208 is an alpha emitter. Write the equation for the nuclear decay of ²⁰⁸Po. Hint: use a periodic table!

A11.Tin-126 is a beta emitter. Write the equation for the nuclear decay of ¹²⁶Sn. Hint: use a periodic table!

Answer 1

What is an alpha particle? What do the numbers 4 and 2 refer in the symbols for the alpha particle? Why is He used sometimes in the symbol for the alpha particle?

Solution :-

Alpha particle is nothing but the helium nuclei

4is the mass number and 2 is the atomic number

Since He has same atomic number and mass number as alpha particle therefore to denote the alpha particle some time He is used.

What happens to a nucleus when alpha radiation occurs?

Solution :- When alpha decay happens then atomic number decreases by 2 and mass number decreases by 4

What is a beta particle? What do the numbers 0 and -1 refer to in ⁰_-1e? Why is e used as part of the symbol for the beta particle?

Solution :- A beta particle is similar to that of electron

0 is the number to indicate the mass number and -1 indicates the atomic number

What reaction is happening inside the nucleus of an atom when beta radiation occurs?

Solution :- When beta particle radiation happens then neutrons are converted to the protons therefore the daughter nuclei have atomic number greater by 1 unit than parent nuclei.

What is the symbol for gamma radiation? What do the two zeros to refer in ⁰₀γ? What is gamma radiation? What happens to the nucleus of an atom when it occurs?

Solution :-

Gamma () is the symbol for the gamma particle. The 0 , 0 indicates that during the gamma radiation no change is taking place in the atomic number and mass number.

To what do the numbers 0 and 1 refer in the positron symbol? Why is e used as part of the positron symbol? What reaction is happening inside the nucleus of an atom when positron radiation occurs?

Solution :- I nthe positron emission process atomic number decrease by unit 1 means proton is converted to the neutron so mass number remains same

Therefore 0 indicates no change in mass number and -1 indicates decrease in atomic number by unit 1

What do all five type of spontaneous nuclear reactions have in common?

  Solution :- In all nuclear reaction the higher nulcie are converted to small nuclei or the unstable element is converted to stable element by nuclear decay process and it also gives of energy.

A10.Polonium-208 is an alpha emitter. Write the equation for the nuclear decay of ²⁰⁸Po.

Solution :- in the alpha decay atomic number decreases by 2 and mass number decreases by 4

So the equation is as follows

²⁰⁸Po ----- > ²⁰⁴Pb   + ⁴₂He

A11.Tin-126 is a beta emitter. Write the equation for the nuclear decay of ¹²⁶Sn. Hint: use a periodic table!

Solution :- equation is as follows

¹²⁶Sn   ------- > ¹²⁶Sb   + ^o_-1e