science - unit 2 vocab

empirical formula

shows us what goes in and what comes out (simplified)

molecular formula

shows EXACTLY how much goes in and comes out (not simplified)

(lewis dot) structural model

shows the atoms, valence electrons, and the type of bond. this is the most common model

ball and stick model

shows the atoms and bonds, which is a quicker version than the most common model

space-filling model

the most accurate representation of what the atoms look like when bonded but shows little useful information

molecules

a single building block created from atoms

compound

the building that creates atoms

covalent bonds

form molecules naturally. if the molecules come together with a different type of atom they will become a larger compound

ionic bonds

never bond with an atom of the same type, so these bonds form compounds naturally and never form molecules, have formula units, electron spends so much time around one atom that it never returns to the original one and is completely transferred

formula unit

the lowest whole number ratio of ions in an ionic compound.

electronegativity difference

found by subtracting the values of both atoms

non-polar

the electron doesn’t favor one atom

polar

the electron will spend more time around one atom (the more electronegative one) than the other

mono

one

di

two

tri

three

tetra

four

penta

five

hexa

six

hepta

seven

octa

eight

covalent bond formulas

* prefix
* the suffix “ide” for second element

ionic bond formulas

* the suffix “ide” for second element
* transition metals have a roman numeral

polyatomic bond formulas

* if it doesn’t end with “ide”, look at cheat sheet