CHEM200 QUIZ2 REVIEW

Number of protons in the nucleus

Atoms of the same element with different number of neutrons

I.E. Carbon (C) has atomic # 6 (All atoms have 6 protons). It may also have 6, 7, or 8 neutrons.

• Therefore relative mass of C is 12,13, or 14.
• carbon-12 (¹²C), carbon-13 (¹³C), etc...

Total number of nucleons (protons and neutrons)

• Z=Atomic #
• A=Mass #
• I.E. ⁴ He 2prtons, 2 neutrons, 2 electrons
• ₂

• I.E. ²³ Na sodium-23 (11 protons and 12 neutrons)
• ₁₁

• Average mass of all isotopes
• Units= amu

• I.E. isotopes of O are:
• ¹⁶O (99.762%, exact mass 15.99491 amu)
• ¹⁷O (0.038%, exact mass 16.99913 amu)
• ¹⁸O (0.200%, exact mass 17.99916 amu)
• So, atomic weight of O is
• =(0.99762(15.99491amu)+0.00038(16.99913amu)+0.00200(17.99916amu)
• =15.9993amu

Alkali metals (except Hydrogen)

Alkaline earth metals

Halogens

Noble gases

• When an atom (electrical neutral) loses or gains electrons
• -Gains becomes negative "anion"
• -Loses becomes positive "cation"

• Held by attraction between opposite charge ions.
• *Usually between metals and non-metals

Greater the attraction

I.E. Down the periodic table the larger the radius

Metal and Non-metal (ionic bond)

• Naming:
• Name the metal (for variable charge metals include Roman numeral) and then name the non-metal changing ending to ide
• I.E. MgCl₂ magnesium chloride

Non-metal and Non-metal (covalent bond... electron sharing)

• Naming:
• use prefixes to indicate # of atoms of first and second non-metal; add ide to the ending
• I.E. P₂S₅ diphosphorus pentasulfide

• Groups IA, IIA, and IIIA have only one possible charge:
• +1 for IA, +2 for IIA, and +3 for IIA

Ag +1, Zn +2, and Cd +2

Transition metals

Compound that has cation or anion that is a polyatomic ion

• Naming: cation then anion (or vice-versa)
• I.E. KMnO₄ Potassium permanganate
• Al₂(SO₄)₃ Aluminum sulfate

• Start with hydrogen (usually aqueous solution)
• I.E. HCl_(aq)

H and another element

• Naming: Hydro----ic Acid
• I.E. HBr is hydrobromic acid

Contain polyatomic ion

• Naming:
• 1. anion ends in ate then -----ic acid
• I.E. HNO₃ nitric acid

• 2. anion ends in ite then -----ous acid
• I.E. HNO₂ nitrous acid

Ionic Compound with exact number of water molecules bound to each crystal

• Naming: use prefixes for the number of water molecules
• I.E. MgSO₄~7H₂O Magnesium sulfate heptahydrate