P5.1 The nucleus

Describe the composition of the nucleus

• Composed of positively charged protons and neutrally charged neutrons

  • The nucleus has a positive charge

State the relative charges, mass and location of the main subatomic particles

Subatomic Particle	Location	Mass	Relative Charge
Protons	Nucleus	1	+1
Neutrons	Nucleus	1	No charge
Electrons	Shell	0	-1

How do you calculate nuclear charge?

number of protons in the nucleus x relative charge of a proton (1)

Define proton number (Z)

• Proton number: amount of protons in an atom, determines the atomic number

  • Number of protons determines the element it is

Define nucleon number (A)

• Nucleon number: total number of particles in the nucleus of an atom (protons + neutrons), determines mass number

How to calculate neutron number?

• nucleon number - proton number

Use nuclide notation

What is nuclear fission?

• The process of splitting a large, unstable nucleus into two smaller nuclei

Describe the process of nuclear fission

• Neutron collides with the large, unstable nucleus (reactants)

• The nucleus splits into two smaller nuclei (products)

• Gamma rays are emitted during this process

What is nuclear fusion?

• The process of joining two light nuclei to form a single, heavier nucleus

Describe the process of nuclear fusion

• Two light, atomic nuclei merge to form a single, heavier nucleus

• Energy is released during this process

• Because of this, the mass of the product will be less than the combined mass of the reactants since some of it was converted into energy