Chemistry unit 2: Atoms, molecules, and Ions

Atom is…

The smallest part of an element

Atoms contain…

Protons(+), Electrons(-), Neutrons(0)

Format for element

All atoms of the same element have…

the same # of protons

Format for element symbol notation

Atomic # = Z (Bottom), Mass # = A (Top) = Protons + Neutrons

Isotopes

Atoms of the same element with different masses & have different numbers of Neutrons

Ions

Elements that gain or lose an e-.

Metals lose e- = Gain a positive charge

Nonmentals gain e- (become anions) = gain a negative charge

Ionic Compounds

Form bonds by transfer of e- + the overall electrical charge of the compound is zero, because the positive charges of the metal ions balance out the negative charges of the non-metal ions

Naming Metal + Nonmetal(Ionic Compounds)

Cross method for name to symbol. + Metal name stays the same. nonmental drops ending for -ide.

Ionic Compounds (Metal + Polyatomic)

Nonmetal + Polyatomics (still use Criss cross method)

Polyatomic ion: $NH_4^+$

Ammonium

Polyatomic ion: $CO_3^{2-}$

Carbonate

Polyatomic ion: $OH^-$

Hydroxide

Polyatomic ion: $NO_3^-$

Nitrate

Polyatomic ion: $NO_2^-$

Nitrite

Polyatomic ion: $CN^-$

Cyanide

Polyatomic ion: $SO_4^{2-}$

Sulfate

Polyatomic ion: $SO_3^{2-}$

Sulfite

Polyatomic ion: $PO_4^{3-}$

Phosphate

Polyatomic ion: $C_2H_3O_2^-$

Acetate

Polyatomic ion: $NH_4^+$

Ammonium

Polyatomic ion: $CO_3^{2-}$

Carbonate

Polyatomic ion: $OH^-$

Hydroxide

Polyatomic ion: $PO_4^{3-}$

Phosphate

Polyatomic ion: $NO_3^-$

Nitrate

Polyatomic ion: $SO_3^{2-}$

Sulfite

Polyatomic ion: $NO_2^-$

Nitrite

Polyatomic ion: $C_2H_3O_2^-$

Acetate

Polyatomic ion: $HCO_3^-$

Hydrogen carbonate

Polyatomic ion: $CN^-$

Cyanide

Polyatomic ion: $SO_4^{2-}$

Sulfate

Polyatomic ion: $HSO_4^-$

Hydrogen sulfate

Transition Metal

• Charges not set(can change)

• when naming, must use roman numerals to tell charge

Transition metal formula to name

Quantity of Transition metal x element charge(unknown) times Element 2 quantity times the charge = 0

Covalent Compounds

• 2 or more nonmetals

• Share e-

• Use prefixes

• Nonmetal is still -ide

• Mono not used for first element

Prefixes

Mono - 1

di - 2

tri - 3

tetra - 4

penta - 5

hexa - 6

hepta - 7

octa - 8

mona - 9

deca - 10