Nuclear Binding Energy
To obtain the most precise value of the binding energy per nucleon, it is important to take into account forces between nucleons at the surface of the nucleus. Will surface effects increase or decrease estimates of BEN?
Unit 1 - Chemical Bondings & Water 3 Classes of Chemical Bonds • Covalent bonds - a pair of electron is shared by two other atoms, which allows the atom to fill it’s outer valance shell (e.g two hydrogen atoms to form a hydrogen molecule). • Polar covalent bonds. • Non polar covalent bonds. • Molecules can have both polar and non polar covalent bonds. Number of covalent bonds in common elements. Hydrogen 1 Oxygen & Sulfur 2 Nitrogen 3 Carbon (important to all organic chemistry) 4 Phosphorus 5 • Ionic bonds - two oppositely charged ions attract each other. Often when an atom of higher electronegativity takes the electron of an atom with lower electronegativity (e.g Cl taking an electron from Na to form table salt). • Weaker than covalent bonds, but still relatively strong. • Hydrogen bonds - the existence of two polar covalent bonds. Hydrogen bonds are the weakest out of the three. An Introduction on Water • Water covers 75% of the earth’s surface and takes up roughly 95% in mass of cells. • Universal solvent for life, most cells thrive and live in aqueous environments. • The five important properties of water: 1. Water of cohesive. 2. Water has a high heat capacity. 3. Water has high heat of evaporation.