Bio A1

Cells are composed of millions of molecules and ions

Only Neutral Atoms with Stable Electron Configurations - Noble Gases (He, Ne, Ar, Kr, Xe)

• Because they have full valence shell electrons

  The other atoms, can only be stable by combining with other atoms

  1. Covalent Bonds (sharing)

  2. Ionic Bonds (give and take)

Polarity

Many covalent bonds are called "polar covalent", these bonds have "dipoles"

• Polar Covalent: The electrons are not equally shared 

  • They are considered to be in stable equilibrium and are therefore neutral

• Dipole: Regions with slight positive and negative natures, which result from the unequal distribution of electrons in regions of the molecule.

A positive dipole exists when there is an absence of electrons

A negative dipole exists when there is an abundance of electrons