NUCLEAR CHEMISTRY

WHAT IS AN ATOMIC NUCLEUS?

• It is the center of an atom
• It is made up of protons and neutrons
• Surrounded by electrons that orbit the nucleus
• Protons have a positive charge and neutrons have no charge
• This makes the nucleus positive

WHAT DOES THE ATOMIC MASS AND ATOMIC NUMBER TELL US?

• The atomic number is the number of protons in a nucleus.
• The atomic number tells us the charge of specific atoms
• Neutral atoms number is the number of electrons
• The atomic mass is the number of nucleons in an atom
• Or the total number of protons and electrons in an atoms

What is an Isotope?

• Isotopes are variations of elements.
• They have the same number of protons
• But a different number of neutrons

HOW CAN THE SAME ELEMENT HAVE DIFFERENT ISOTOPES?

• One element can have many different numbers of neutrons
• Making many different isotopes

What is the difference between stable and unstable isotopes?

• Stable isotopes maintain constant concentrations on earth overtime
• unstable isotopes are atoms that decay over time
• They emit a nuclear electron or a helium nucleus and radiation
• They do this to try and become stable
• They continue to decay until they are stable

WHAT IS NUCLEAR DECAY?

• It is the process by which an unstable atom loses energy
• They do so by emitting particles of ionizing radiation
• These particles carry enough energy to liberate an electron from an atom
• They do this by ionizing it- giving it a positive or negative charge

ALPHA DECAY

• The nucleus has too many protons
• Causes the particles to move away from each other
• To stop this a helium nucleus (2 protons 2 neutrons) is released
• The helium nucleus collides with the wall of the nucleus and tunnels out

BETA DECAY

• The neutron to proton ratio is too big
• Causes instability
• A neutron is turned into a proton
• An electron is released

POSITRON EMISSION

• When the neutron to proton ratio is too small
• A proton turns into a neutron
• A positively charged electron- positron- is released

ELECTRON CAPTURE

• Neutron to proton ratio is too small
• Nucleus captures an electron
• Basically making a proton a neutron

GAMMA DECAY

• The nucleus has too much energy
• The nucleus fall down to a lower energy level
• Emits a high energy photon known as a gamma particle