Calculate the “theoretical” mass of an alpha Calculate the “theoretical” mass of an alpha particle, using:particle, using:Proton mass Proton mass = 1.67338 x 10 = 1.67338 x 10-27 -27 kgkgNeutron mass = 1.67483 x 10Neutron mass = 1.67483 x 10-27 -27 kgkg

2p + 2n = 6.69642 x 102p + 2n = 6.69642 x 10-27-27kgkg

Do now:Do now:Thursday, April 20, 2023

The The actualactual mass of an alpha particle has mass of an alpha particle has been measured to be 6.64591 x 10been measured to be 6.64591 x 10-27 -27 kgkg

What’s going on???What’s going on???

Explain this “mass deficit” in terms of Explain this “mass deficit” in terms of nuclear binding energy nuclear binding energy

Use the concept of binding energy per Use the concept of binding energy per nucleon to explain the stability of nucleinucleon to explain the stability of nuclei

Today’s Learning:Today’s Learning:

I’m away on Wed: so time for you to I’m away on Wed: so time for you to complete Activity 12A and 12Bcomplete Activity 12A and 12B

H/W Set 3 due next Mon 25H/W Set 3 due next Mon 25thth March March

Notices:Notices:

I’m away on Wed: so time for you to I’m away on Wed: so time for you to complete Activity 12A and 12Bcomplete Activity 12A and 12B

H/W Set 3 due next Mon 25H/W Set 3 due next Mon 25thth March March

Waves test: re-sit Thursday lunchtime (S2)Waves test: re-sit Thursday lunchtime (S2)

- compulsory for anyone who scored “N”- compulsory for anyone who scored “N”

- recommended for anyone who scored < 12/24- recommended for anyone who scored < 12/24

Notices:Notices:

Binding EnergyBinding Energy

Mass number50 100 150 200

Binding energy

per nucleon

(MeV)

2

4

6

856Fe

238U4He

7Li

Fusion Fission