Chap 3 Part B - Sheet1 Flashcards
(22 cards)
octet rule
main group elements tend undergo reactions leave them with eight valence electrons
transition metals form cations or anions
cations, but can lose one or more d electrons in addition to losing valence s electrons. OCTET rule not followed.
How do metals form cations or anions?
Metals form cations by losing one or more electrons. Group 1A and 2A metals form +1 and +2 ions, respectively, to achieve a noble gas configuration. Transition metals can form cations of more than one charge by losing a combination of valence-shell s electrons and inner-shell d electrons.
How do nonmetals become anions or cations
Reactive nonmetals form anions by gaining one or more electrons to achieve a noble gas configuration. Group 6A nonmetals oxygen and sulfur form the anions O2– and S2–. Group 7A elements (the halogens) form –1 ions.
Do Noble gases form anions or cations?
Group 8A elements (the noble gases) are unreactive.
how does the group number inform one regarding the charge of the group
For 1A and 2A metals, cation charge = group number. For nonmetals in groups 5A, 6A, and 7A, anion charge = 8 – (group number).
naming ions main group metal cations
idendify metal then add word ion. K+ is potassium ion.
naming ions main group anions
Anions are named by replacing the ending of the element name with -ide, followed by the word “ion.”
Cl- is chloride ion
naming transition metal cations
copper is either Cu+ copper (I) or Cu2+ copper(II) the 2 is superscript
polyatomic ion
Polyatomic ionAn ion that is composed of more than one atom.
how are polyatomic ions held together?
The atoms in a polyatomic ion are held together by covalent bonds.
A polyatomic ion is charged because it contains a total number of electrons that is different from the total number of protons in the combined atoms.
These ions are encountered so frequently that it is essential to memorize their names and formulas.
formula unit
Formula unitThe formula that identifies the smallest neutral unit of an ionic compound
formula for ionic compounds
2 K(1+super) + O(2-super) becomes K(sub2)O
formula ionic compounds
Mg(super 2+) and PO(subscript 4)(super 3-) you swap the charges and make them subscripts and drop charges Mg(sub 3)(PO(sub4)(sub2).
acid
substance that provides H+ ions in water
base
substance that provides OH- ions in water
name 2 of most important ions
Two of the most important ions are the hydrogen cation (H+) and the hydroxide anion (OH–).
A hydrogen cation is simply a proton.
what happens when acid dissolves in water
When an acid dissolves in water, the proton attaches to a molecule of water to form a hydronium ion.
H+ + H2O into H3O+
hydroxide anion
OH- polyatomic ion in which an oxygen atom is covalently bonded to a hydrogen atom.
Can acids provide different numbers of H+ ions?
Different acids can provide different numbers of H+ ions per acid molecule.
Hydrochloric acid, HCl, provides one H+ ion per acid molecule.
Sulfuric acid, H2SO4, can provide two H+ ions per acid molecule.
Phosphoric acid, H3PO4, can provide three H+ ions per acid molecule.
What happens when BASES dissolve
When these compounds dissolve, OH– anions go into solution along with the metal cation.
name 2 bases
Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are bases.
