The fundamental concepts of chemistry essential to life revolve around the formation and interaction of various chemical bonds and reactions. Covalent bonds arise when atoms share pairs of valence electrons, with electronegativity determining an atom’
Valence electrons are the electrons in
the outermost energy shell
Orbitals are a region of space
that has electrons that are around
the nucleus
Chemical Bonds
Chemical Reactions-there
are 4 major types of chemical
reactions in biological processes
Redox reactions is when electrons are lost from one atom and gained by another.
- oxidation= when a molecule lost electrons
- reduction= when a molecule gains electrons
Neutralization reactions is when an acid + base= salt and water.
Hydrolysis reactions is the opposite of dehydration where water is used as a reactant to split a large molecule
Dehydration Reactions (condensation) is when OH & H are removed from 2 reactants then form together to make a H2O and the reactants form together. They are mostly used to create larger molecules like carbs and proteins
Intermolecular forces is the force or attraction between
2 molecules
- a.k.a van der Walls forces are very weak attractions between 2 molecules or parts of molecules, when they are close together
Hydrogen bonds are the attractive force
2 partially positively charged hydrogen atom
& a partially negatively charged atom in another
molecule. They are the strongest bonds VDW
force but individual bonds are weak compared to
ionic and covalent bonds
Polar Covalent Bond is the unequal sharing of electrons between 2 atoms with different electronegativity.
Covalent Bonds form when atoms share one or more pairs of valence electrons.
- Electronegativity is the measure of an atom's attraction for additional electrons. It will increase as the distance between the electrons & the nucleus decrease
Ionic bonds are formed between atoms that
have gained/lost electrons to become charged
- positive ion = cation
- negative ion = anion
Atomic Structure
Radioisotopes is a radioactive isotope of an element
Isotopes are different forms of the same element with different atomic masses (different number of neutrons)
- atomic number= number of protons
- mass number= protons + neutrons
- the bottom number is the atomic number
