Chapter 2 Flashcards
element
A substance that cannot be broken down into other substances by chemical reaction
compound
Substance consisting of two or more different elements combined in a fixed ratio.
What 4 elements make up 96% of living matter?
Carbon
Hydrogen
Oxygen
Nitrogen
What are trace elements? Name a few
Elements that organisms need in minute quantities such as iron and iodine.
List and describe the subatomic particles.
Neutrons-no charge
Protons +
Electrons-
What is an isotope?
Two atoms of an element that differ in number of neutrons.
What are valence electrons?
Electrons in the outer most valence shell
Distinguish between covalent and ionic bonds.
Covalent-the sharing of a pair of valence electrons by two atoms
Ionic -an attraction between an anion and a cation
What is electronegativity?
An atoms attraction for the electrons in a covalent bond.
Distinguish between polar and nonpolar molecules. How does electronegativity relate to polarity?
Electronegativity-the attraction of a particular kind of atom for the electrons of a covalent bond.
Nonpolar-in a covalent bond between atoms of the same element, electrons are shared equally with no tug of war
Polarity-one atom is bonded to a more electronegative atom. The electrons of the bond are not share equally.
Distinguish between reactants and products.
Reactants-the starting molecules of a chemical reaction
Product-the final molecules of a chemical reaction.
What is chemical equilibrium?
Reached when the forward and reverse reaction rates are equal.
