Week 2: Atomic Structure & Biomolecules Flashcards
atoms are made up of
protons, neutrons, and electrons
4 most important atoms for living things
hydrogen, carbon, nitrogen, and oxygen
atomic number
the number of protons in an atom’s nucleus
atomic mass
the sum of protons and neutrons in the nucleus
the closer an electron is to the nucleus
the more tightly it is held to the atom, making it more stable
the chemical reactivity of an atom depends on the state of
it;s outermost electron shell
electron affinities
how strongly an atom can attract an electron
ionic bonds
occurs when a positively and negatively charged ion attract one another
covalent bons
occur when two atoms share an electron to complete their shells
non-polar covalent bonds
share electrons equally between the atoms that make up the bond bc of identical electron affinities
polar covalent bonds
share electrons unequally bw the atoms that make up the bond bc of different electron affinities
the unequal sharing of electrons in polar covalent bonds results in
molecule that has a slight charge difference across the individual molecule (hydrogen bonding)
the polarity of a molecule will define its ability to
interact with water
hydrophilic
polar and ionic compounds
hydrophobic
non polar compounds