P4 - Atomic Structure Flashcards
Scientific models can change over time.This happens when
New evidence is found that can’t be explained by the current model
What is the current model of the atom
Nucleur model of the atom is a nuclear model.This means there is a nucleus in the middle surrounded by electrons.The nucleus is tiny but it makes up most of the mass.Nucleus is made up of protons and electrons
How can electrons move between energy levels
Electrons can move between energy levels by absorbing or releasing electromagnetic radiation
What is an isotope
Atoms of the same element with the same number of protons but a different number of neutrons are called isotopes
Some isotopes are unstable
They emit radiation from their nuclei to try and become more stable.This process is called radioactive decay
What is alpha particles ionising power
Very good
What is alpha decay
Alpha decay is when an alpha particle is emitted from a radioactive nucleus
What are alpha particles made up of
Made up of two peotons and two neutrons
What is beta decay
When a beta particle is emitted from a radioactive nucleus .During beta decay, a neutron in the nucleus turns into a proton.
What is gamma decay
Gamma radiation is emitted by an unstable nuclei after an alpha or beta particle.
What is half life
The half life is the time taken for the number of nuclei of a radioactive isotope in a sample to halve
