Lecture 2 Flashcards
(20 cards)
atom
The smallest unit of matter
chemical bond
An attraction between two atoms, resulting from a sharing of outer shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.
chemical reaction
The making and breaking of chemical bonds, leading to changes in the composition of matter
compound
A substance consisting of 2 or more different elements.
covalent bond
A type of strong (the strongest) chemical bond in which 2 atoms share one or more pairs of valence electrons.
electron shell
An energy level of electrons at a characteristic average distance from the nucleus of an atom
Note: The first shell has 1 orbital. The rest have 2.
electron
Sub-atomic particle with a single neg. charge.
element
Any substance that can’t be broken down to any other substance by chemical reactions.
hydrogen bond
The weakest chemical bond. Happens when polar covalent bonds are attracted to each other.
ion
Atom/atoms that have gained or lost an electron resulting in a pos./neg. charge.
ionic bond
Middle strength chemical bond. Results from attraction of oppositely charged ions.
isotope
One of several atomic forms of an element. Same number of protons but different neutrons, thus differeing in atomic mass
molecular formula
The recipe of a molecule
molecule
Two or more atoms held together by covalent bonds.
neutron
Sub-atomic particle with no electrical charge. Found in nucleus of atom.
product
A material resulting from a chemical reaction
proton
Sub-atomic particle with a single pos. charge. Found in the nucleus.
reactant
A starting material in a chemical reaction
structural formula
A diagram of an atom/molecule showing the distribution of electrons.
valence
The bonding capacity of a given atom. The number of covalent bonds an atom can form usually equals the number of unpaired electrons in it’s outermost (valence) shell.
