HYDROGEN : H was recognized as a distinct substance in 1766 by Henry Cavendish; it is the most abundant of all elements in the universe and it forms more compounds than any other element; common names for isotopes are Deuterium (D) and Tritium (T) (respectively). H is an odorless, colorless gas; H burns in air to form water; reacts with O2, halogens, metals, non- metals; forms hydrides; ^1H 99.985% ^2H 0.015% ^3H 12.3 yrs H is explosive in air. HELIUM: He was discovered between 1868 & 1895 by Sir William Ramsay and others; at ordinary pressure, it stays liquid down to absolute zero; the liquid is used in cryoscopy. He is an odorless, color- less gas; He is inert/unreactive; slight reactive tendancy toward Ne; ^3He <0.00001% ^4He 100% ^6He 0.8 sec He is inert. LITHIUM: Li was discovered by Johann Arfvedson in 1817; it occurs naturally in minerals like amblygonite, lepidolite, petalite & spodumene; it is not miscible with molten K, Rb, & Cs & barely reacts with liq. Br2; a unique property is its reactivity with N2 to give a ruby-red crystal- line nitride Li3N; it can be used to remove nitrogen from other gases and forms Li2O when burned in air/oxygen; it also tarnishes in air; the ionic radius shown is for +1, CN 6; value for +1, CN 4 is 0.59. Li is a silvery metal; lightest of all metals; Li is solu. in liq. ammonia & alcohols; reacts with liq. Br2, H2O, C, H, O2, alcohols; ^6Li 7.5% ^7Li 92.5% ^8Li 0.8 sec None. BERYLLIUM: Be was discovered in 1798 by Louis Vauquelin and isolated (independently) in 1828 by Friedrich Wohler and A. A. Bussy; it is also called Glucinium; Be is found naturally as beryl [Be3Al2(SiO3)6], often occurring as large, hexagonal prisms; because of its surface oxide film, it is resistant to acids when not finely divided or amalgamated; it dissolves (within this order) in dilute HF > H2SO4 HCl > HNO3; rapid dissolution in 3M H2SO4 & 5M NH4F; forms beryllate ion in strong bases. Be is a hard & brittle gray metal; Be is solu. in water, acids, & bases; reacts with halogens & bases;  ^7Be 53.25 days ^9Be 100% ^1^0Be 1.5 mill. yrs ^1^1Be 13.8 sec Be is toxic -- handle with great care! SODIUM: Na was isolated by Sir Humphry Davy in 1807; it occurs naturally as NaCl as well as in minerals like cryolite, soda niter, zeolite, etc; also occurs in high abundance in lithosphere (2.6%); liq. Na is studied as a nuclear reactor coolant; Na forms the Na-K alloy & is miscible with other Group I elements although Li is a weak mix; shows fast reaction in mercury, vigorous reaction in water, but barely reacts with liq. Br2; reactions in alcohols form alkoxides; ionic radius given is for +1, CN 9; value for +1, CN 6 is 1.02. Na is a silvery metal Na is solu. in liq. ammonia, mercury & alco- hols; reacts with H2O, liq. Br2, C, H, O2, alcohols; ^2^1Na 22.5 sec ^2^2Na 2.6 yrs ^2^3Na 100% ^2^4Na 15 hrs Spontaneous ignition in water. MAGNESIUM: Mg was first recognized as an element in 1755 by Joseph Black; Sir Humphry Davy then isolated it in 1808; it is the eighth most abundant element in earth's crust, and it also occurs in the sea & in minerals like dolomite (CaCO3MgCO3] and carnallite (MgCl2KCl6(H20)); it is attacked by alkyl & aryl halides in ether to give Grignard; Mg burns readily in air when finely divided; water should not be used to put out a Mg fire. Mg is a grayish, white, tough metal; Mg is solu. in dilute acids; reacts with halides; ^2^4Mg 78.99% ^2^5Mg 10.00% ^2^6Mg 11.01% ^2^7Mg 9.45 min ^2^8Mg 21 hrs May flame up (pwdr) in air. BORON: Both Sir Humphry Davy and the pair Joseph Louis Gay-Lussac & Louis Jacques Thenard discovered B (independently) in 1808; it occurs in nature as borax [Na2B4O5(OH)48(H2O)], kernite [Na2B4O5(OH)42(H2O)], tourmaline, & ulexite; it is always trivalent, and its most stable form is the amorphous brownish-black solid for which data is given; specific gravity of the yellowish crystal form is 2.34; this yellow form is extremely inert and not affected by boiling HCl or HF. Hot, conc. HNO3 will slowly oxidize this crystalline form when it is finely pwdered. B is a hard, brown-black solid. B is solu. in hot conc. HNO3; very corrosive & forms some B-H cmp'ds.  ^8B 0.77 sec ^1^0B 19.9% ^1^1B 80.1% B is toxic and very corrosive needing special care. CARBON: C has been known since ancient times; it is the hardest known solid and is found free in nature; it has four forms: amorphous black with spec. grav. of 1.8 to 2.1; hexagonal, black graphite with spec. grav. of 1.9 to 2.3; diamond, for which data is given, and "white" carbon which is thought to exist; graphite sublimation is at 3367 25C and its magnetic susceptibility is -6.0 (10^-^6 cgs); graphite's density is 2.22 g/cm^3; graphite is more stable than diamond; somewhere near ten million carbon compounds are known to exist, and its chemistry is quite extensive; it is the basis for life itself. C is a hard, colorless solid C usually forms covalent bonds; very extensive solu. and reactivity! ^1^0C 19.3 sec ^1^1C 20.3 min ^1^2C 98.9% ^1^3C 1.1% ^1^4C 5715 yrs None. NITROGEN: N was discovered by Daniel Rutherford in 1772; it occurs naturally as N2 in about 78% by volume of the earth's atmousphere; N has two allotropes, and the -form -> -form transition occurs at -237C; forms some stable cmpd's with incomplete octets; CAS# given for N2; CAS # for N is 17778-88-0. N is a colorless, odor- less gas. N reacts w/ lithium and several transition metal complexes. ^1^3N 10 min ^1^4N 99.63% ^1^5N 0.37% ^1^6N 7.1 sec None. OXYGEN: O was discovered by Joseph Priestly; it occurs naturally as a mixture of ^1^6O(99.759%), ^1^7O (0.0374%), and ^1^8O (0.2039%); ^1^8O is used as a tracer; Oxygen has two allotropic forms: O2 (stable) & O3 (ozone) which is highly reactive; upon heating, it combines with almost all other elements and is readily soluable in organic solvents (even just by pouring solvents in air); the ionic radius given is for O^-^2, CN 6; for O^-^2, CN 3 it is 1.36; CAS# given is for O2; for O it is 17778-80-2. O is a pale blue, odor- less, tasteless gas. O is reacts w/ & is readily solu. in many compounds. ^1^4O 1.18 min ^1^5O 2 min ^1^6O 99.76% ^1^7O 0.04% ^1^8O 0.20% O is non-toxic, however ozone is quite dangerous. FLUORINE: F was isolated by Henri Moisson in 1886; it occurs naturally as com- pounds like F2, cryolite (Na3AlF6), fluorapatite [3(Ca3)((PO4)2)Ca(F,Cl)2, or fluorite (CaF2); F is the most chemically reactive (often extremely vigorous) of all elements; it may be possible to substitute flourine for hydrogen wherever H occurs in organic compounds; organic compounds often inflame or burn when attacked by F; free floating flourine has a detectable, strong smell; the given CAS# is for F2; CAS# for F is 14762-94-8; F is generally handled in metal apparatus. F is a yellow gas. F is corrosive and reactive with most elements except light noble gases, O2 & N2. ^1^7F 1.08 min ^1^8F 1.8 hrs ^1^9F 100% ^2^0F 11 sec F is highly toxic; handle with care! NEON: Ne was discovered in 1898 by Sir William Ramsay & Morris William Travers; it occurs naturally in air at 0.00182% and is often used in discharge tubes for its red-orange spectral emissions; Ne is listed as ferromagnetic; it is basically unreactive but may react with flourine, and it may form cations alone or with H, He, or Ar. Ne is a colorless gas. Ne is very unreactive but may react w/ F. ^2^0Ne 90.48% ^2^1Ne 0.27% ^2^2Ne 9.25% ^2^3Ne 37 sec ^2^4Ne 3.4 min None. ALUMINUM: Al was discovered (or isolated) by Friedrich Whler in 1827; it occurs naturally in silicates such as feldspars & micas, as bauxite, and as cryolite (Na3AlF6) and is terrestrially the most abundant metal; Al forms cationic complexes and resists corrosion because of formation of a tough oxide film on its surface; it is also soluable in a mixture of HCl with CuCl2 (see Chemical Properties too); the ionic radius given is for Al^+^3, CN 6; for Al^+^3, CN 4 the ionic radius is 0.39; the magn. susc. for liq. Al is 12.0 x 10^-^6 cgs. Al is a hard, strong, white metal. Al is solu. in dil. mineral acids or NaOH, passivated in conc. HNO3; attacked by hot alkali hydroxides, halogens, and various non-metals. ^2^6Al 0.7 mill. yrs ^2^7Al 100% ^2^8Al 2.25 min ^2^9Al 6.5 min Al is non-toxic. SILICON: Jns Berzelius discovered Si in 1824; approximately 28% of the earth's crust is Si, and it also occurs in many oxide and silicate compounds such as agate, asbestos, clay, flint, granite, quartz, sand, etc.; the amorphous form is a brown powder while the crystalline form has a metallic luster and a gray color; given is the ionic radius is for Si^+^4 CN 4; while Si is generally harmless, cutting of Si compounds can pro- duce a dust which leads to a dangerous lung disease called silicosis. Si is a gray, metallic solid. Si is solu. in HF; fairly unreactive, but attacked by halogens, alkalis & HF. ^2^8Si 92.23% ^2^9Si 4.67% ^3^0Si 3.10% ^3^1Si 2.6 hrs ^3^2Si 160 yrs Si exhibits danger as silicosis from Si compounds. PHOSPHORUS: Hennig Brand discovered P in 1669; there are many phosphate minerals in which it occurs naturally; there are 3 forms of phosphorous: white which is highly reactive & toxic (and for which data is given), black which is formed by heating white under pressure, and red which is obtained by heating white in a sealed vessel; the respective stabili- ties are: white < red < black, however, all forms eventually return to white; white has an -form and a -form with transition occuring at -3.8C; additional densities are red = 2.34 g/cm^3, and black = 2.70 g/cm^3; additional magn. susc. are red = -20.8 x 10^-^6 cgs, black = -26.6 x 10^-^6 cgs; the ionic radius for P^+^3 is 2.12; store white P under water. P is a soft, white, waxy solid; also red, black, & (violet?) forms. P is soluable in CS2 or benzene; it reacts w/ H, O, N, halogens, & many organic cmp'ds. ^3^0P 2.5 min ^3^1P 100% ^3^2P 14.3 days ^3^3P 25 days P is poisonous, flames in air. SULFUR: S has been in use for a long period of time; it occurs naturally as H2S, SO2, and in sulfide minerals & sulfates such as anhydrite, galena, celestite, barite, and so on; sulfur is often found by volcanos and hot springs; cyclo-S8 is the common form; however, it transforms to the monoclinic -form at 95.5C; it also forms rings of 6 to 12, 18, or 20 atoms; it is a good electrical insulator and is used primarily for manufacturing sulfuric acid, vulcanizing rubber, and making a sulfides (like CS2 & P2S5); the ionic radius given is for S^+^6, CN 4; for S^+^6, CN 6 it is 0.29; additionally, the potential for S + 2e^- -> S^2^- is -0.47627 volts; sulfur is solu. in CS2, organic amines, & non-polar solvents like benzene & cyclohexane; it burns in air & reacts with halogens, most metals & non-metals and is not affected by non-oxidizing acids. S is a brittle yellow solid w/ a more rare red form. S is solu. in CS2 & some organic solvents; it burns in air & reacts w/ halogens, most metals & non-metals; ^3^2S 95.02% ^3^3S 0.75% ^3^4S 4.21% ^3^5S 87 days ^3^6S 0.02% S has many dangerous compounds and should be handled w/ care. CHLORINE: Cl was discovered by Carl Wilhelm Scheele in 1774; it occurs naturally as NaCl and, to a lesser extent, as diatomic gas; it is moderately soluable in water with which it reacts, and it is often substituted for H where H exists in organic molecules; Cl is very reactive; the given CAS# is for Cl2; for Cl the reference # is not known. Cl is a pale, greenish gas Cl reacts w/ nearly all elements and, to some extent, water. ^3^5Cl 76% ^3^6Cl 0.3 mill. yrs ^3^7Cl 24% ^3^8Cl 37 min ^3^9Cl 55.6 min Cl is a toxic respiratory & skin irritant; ARGON: Ar was discovered by Lord Rayleigh & Sir William Ramsay in 1894; it occurs naturally as 0.934% in air; it is very unreactive and is used primarily for welding & in gas filled electric light bulbs. Ar is colorless & odorless; Ar forms cations w/ Ne, Kr, & Xe & is solu. in water; basically unreactive. ^3^6Ar 0.34% ^3^8Ar 0.06% ^3^9Ar 268 yrs ^4^0Ar 99.60% ^4^2Ar 33 yrs None.