Chapter 2 Vocab Flashcards
Element
Simplest form of matter to have unique chemical properties
Trace elements
Group of 12 elements that make up smallest amount of body composition
Minerals
Inorganic elements that are extracted from the soil by plants and are passed up the food chain to humans and other organisms
Protons
+
Neutrons
No charge
Electron
-
Valence electrons
Electrons of outermost shell that determine chemical bonding properties
Isotopes
Differ from one another in # of neutrons
Radioisotopes
Unstable isotopes
Radioactivity
Process of decay
Physical half-life
Time required for 50% of its atoms to decay to a more stable state
Biological half-life
Time required for half of radioisotope to disappear from the body
Anion
Particle that gains electrons and negative charge
Cation
Particle loses electrons and has positive charge
Electrolytes
Substances that ionize in water and form solutions capable of of conducting electricity
Free radicals
Chemical particles with odd number of electrons
Antioxidants
Chemical that neutralizes free radicals
Compound
Molecule composed of 2+ elements
Isomers
Molecules with identical molecular formulae but different arrangements of their atoms
Molecular weight
Sum of atomic weights of compound’s atoms
Chemical bond
Force that holds molecule together
Ionic bond
Attraction of cation to anion
Covalent bond
Sharing of electrons
Hydrogen bond
Weak attraction between slightly positive hydrogen atom in one molecule and slightly negative oxygen or nitrogen atom in another
Van der Waals forces
Weak, brief attractions between neutral atoms
Biochemistry
Study of molecules that compose living organisms
Hydrophilic
Substances that dissolve in water
Hydrophobic
Substances that do not dissolve in water
