mod 2 definitions Flashcards
matter
anything that has mass or has volume
atomic number
the number of protons in an atom
elements
a collection of atoms that all have the same number of protons
periodic table
a table of chemical elements arranged in order of atomic number
isotopes
one of several forms of an element, each containing the same number of protons but a different number of neutrons
atomic mass
the sum of protons and neutrons in an atom
molecule
chemical that results when two or more atoms join together chemically
compound
a molecule that contains atoms of at least two different elements
ionic bond
a chemical bond formed when two or more electrons are transferred from one atom to another
ion
positively or negatively charged atom (or group of atoms) resulting from the transferring of electrons
covalent bond
chemical bond formed by the sharing of electrons between two or more atoms
polar compound
a molecule in which there is an unequal distribution of the negatively charged electrons causing a partial positive charge at one end and a partial negative charge at the other
hydrogen bond
a weak electrical attraction between a partially positive hydrogen atom and a partially negative atom of another molecule (usually oxygen or nitrogen)
solvent
any substance in which other substances are dissolved
solute
a dissolved substance
solution
a mixture of solutes dissolved in a solvent
aqeuous solution
a solution in which water is that solvent
cohesion
an attractive force that holds molecules of the same substance together
heat capacity
the amount of heat energy required to increase the temperature
organic molecules
molecules found in living organisms that contain carbon in rings or long chains, attached to other atoms like hydrogen, oxygen, nitrogen, sulfur, or phosphorus
biosynthesis
the process by which living organisms produce larger molecules from smaller ones
isomers
two different molecules that have the same chemical formula
monosaccharides
simple sugars; they are the building blocks of more complex carbohydrates
disaccharides
carbohydrates that are made up of two monosaccharides
polysaccharides
carbohydrates that are made up of more than two monosaccharides
dehydration reaction
a chemical reaction in which molecules combine by removing water
starch
a polysaccharide consisting of many glucose molecules stored in one plants
glycogen
a polysaccharide consisting of many glucose molecules stored in animals
cellulose
a polysaccharide consisting of many glucose molecules found in the walls of plants
hydrolysis
breaking down complex molecules by the chemical addition of water
hydrophobic
lacking any affinity to water
saturated fat
a lipid made from fatty acids that have no double bond between carbon atoms
unsaturated fat
a lipid made from fatty acids that have at least one double bond between carbon atoms
steroid
lipid molecule with four fused carbon rings
