Electron Orbitals Each shell can be divided further into subshells, labelled s, p, d and f Each subshell can hold a specific number of orbitals: s subshell : 1 orbital p subshell : 3 orbitals label...
Electron Shells: Basics Shells The arrangement of electrons in an atom is called the electronic configuration Electrons are arranged around the nucleus in principal energy levels or principal quant...
Isotopes: Basics Isotopes are atoms of the same element that contain the same number of protons and electrons but a different number of neutrons The symbol for an isotope is the chemical symbol (or...
Atomic & Ionic Radius Atomic radius The atomic radius of an element is a measure of the size of an atom It is half the distance between the two nuclei of two covalently bonded atoms of the same...
Determining the Subatomic Structure of Atoms & Ions An atom is neutral and has no overall charge Ions on the other hand are formed when atoms either gain or lose electrons, causing them to beco...
Mass & Charge Distribution The mass of an atom is concentrated in the nucleus, because the nucleus contains the heaviest subatomic particles (the neutrons and protons) The mass of the electron ...
Structure of an Atom All matter is composed of atoms, which are the smallest parts of an element that can take place in chemical reactions Atoms are mostly made up of empty space around a very smal...
GMOs in Food: Social & Ethical Implications The genetic modification of microorganisms for the production of medicines, antibiotics and enzymes raises little debate compared to the use of genet...
Genetic Engineering: Use in Agriculture Genetic engineering is a technique used to deliberately modify a specific characteristic (or characteristics) of an organism The technique involves removing ...
Social & Ethical Considerations The use of gene technology (genetic screening and gene therapy) in medicine is becoming more common Genetic screening in medicine is being used to: Allow people ...
Gene Therapy Gene therapy involves using various mechanisms to alter a person's genetic material to treat, or cure, diseases As scientists gain a better understanding of the human genome and theref...
Genetic Screening In certain circumstances (eg. in the pregnancy in an older woman, or pregnancy where there is a family history of a genetic disease) may require individuals to determine if they h...
