Basic Chemistry IVladimíra Kvasnicová

Composition of Matter

• organic / inorganic

compound = a substance formed by chemical reaction;it consists of elements in fixed proportions

element = a substance that cannot be decomposed into simpler substances; it consists of atoms with a same number of protons (number of neutrons may vary)

--------------------------------------------------------------- atom = the smallest part of an element that can

exist chemically molecule = the smallest part of a chemical

compound that can take part in chemical reaction

Composition of Matter

structure of atom• nucleus: protons (p+) + neutrons (n0)• „cloud“ of electrons (e-)

• mass number A (= nucleon number) • proton number Z (= atomic number)• neutron number N• electroneutrality• nuclide• isotopes

Composition of Matter

• inorganic mater oxygen (O) 50% silicon (Si) 25% aluminium (Al) 7% iron (Fe) 5% calcium (Ca) 3%

90%

sodium (Na) potassium (K) magnesium (Mg) hydrogen (H) titanium (Ti) 0,6%

• organic mater„compounds of carbon“

C, O, H, N

carbon (C) oxygen (O) hydrogen (H) nitrogen (N) phosphorus (P) sulfur (S)

• air, blood plasma

Distinguish

• isotopes = atoms having the same proton number but different mass number (isotopes of carbon: 12C, 13C, 14C)

• element = a substance composed of atoms havingthe same proton number (element consists of various isotopes)

• nuclide = a substance composed of atoms havingthe same proton and mass numbers(substance containing only 12C = nuclide called carbon „12“)

• atom / molecule / ion(monoatomic, polyatomic - binary, ternary)

Exercise

• nuclide: AZX

• make groups of:a) isotopesb) the same elementsc) the same nuclides

X 1 2 3 4 5 6 7 8

A 127 235 123 131 238 222 234 125

Z 53 92 53 53 92 86 92 53

Exercise

• nuclide: AZX

• make groups of:a) isotopes: iodine, uraniumb) elements: iodine, uranium, radonc) the same nuclides: 3, 8

X 1 2 3 4 5 6 7 8

A 127 235 123 131 238 222 234 123

Z 53 92 53 53 92 86 92 53

Calculate number of neutrons of 127I

n0 = 74

Memorize

symbols and names of elementsuse flash cards

The figure is found at http://www.corrosionsource.com/handbook/periodic/periodic_table.gif (September 2007)

Symbol Latin name English name

Na Natrium sodium

K Kalium potassium

Sn Stannum tin

Pb Plumbum lead

Sb Stibium antimony

W Wolframium tungsten

Fe Ferrum iron

Cu Cuprum copper

Ag Argentum silver

Au Aurum gold

Hg Hydrargyrum mercury

Composition of Matter

structure of atom – arrangement of electrons

• four quantum numbers

orbital = a region of space in which an electron is most likely to be found

• principal shells → energy• subshells → shape of orbitals• degenerate orbitals → space orientation• spin (rotation) of electrons

Shapes of orbitalsss

ppxx ppyy ppzz

Shapes of orbitals

ddxy ddyz ddzx

ddx 2 – y 2 ddz 2

Composition of Matter

structure of atom – arrangement of electrons

• Pauli´s exclusion principle= no two electrons in the atom can have the same set of quantum numbers

• Hund´s rule= electron will not enter an orbital containing another electron if an empty orbital of the same energy is available

Energy of orbitals

The figure is found at http://www.corrosionsource.com/handbook/periodic/periodic_table.gif (September 2007)

Composition of Matter

structure of atom – arrangement of electrons

• ground / excitated state• valence electrons• radicals

• electronegativity = a measure of the ability of an atom in a molecule to draw bonding electrons to itself

• chemical bonds

The figure is found at http://www.corrosionsource.com/handbook/periodic/periodic_table.gif (September 2007)

the arrow showes increase of

electronegativity

Inorganic Compounds

Oxides anion: O-II

• acid-forming: nonmetal / oxygen use multiple prefixes (mono, di, tri,...)

• base-forming: metal / oxygen use sufixes –ous / -ic or (oxidation state)

• amphoteric

MnO2, N2O, BaO, CO, K2O, SO2, FeO, Cu2O, CaO

Inorganic Compounds

Peroxides anion: O2-2 O-I

• s1 elements (hydrogen and alkali metals): M2O2

• s2 elements (alkali earth metals): MO2

sodium peroxide magnesium peroxide

barium peroxide potassium peroxide

hydrogen peroxide lithium peroxide

Inorganic Compounds

Hydroxides anion: (OH)-1

• basic properties (pH > 7)• strong or weak hydroxides• metal / hydroxide anion

use sufixes –ous / -ic or (oxidation state)

• ammonium / hydroxide anion

NaOH, LiOH, NH4OH, Fe(OH)3, Cu(OH)2, Ca(OH)2

Inorganic Compounds

Acids cation: H+ (pH < 7)

1) oxygen free acids

hydro-...................-ic acid

HF, HCl, HBr, HI, H2S, HCN (in aqueous solutions)

anion: -ide

• monoprotic / diprotic acids

Inorganic Compounds

Acids cation: H+

2) oxoacids the highest oxidative state per-.....-ic acid

higher (or only) oxidative state -ic acid

lower oxidative state -ous acid

the lowest oxidative state hypo-...-ous acid

anion:

-ic acid → -ate

-ous acid → -ite

Inorganic Compounds

Saltsare formed by neutralization:

acid + hydroxide → salt + water

cation: metal or NH4+

derived from the hydroxide (= cation of the hydroxide)

anion: oxygen-free or polyatomic anion derived from the acid (= anion of the acid)

Inorganic Compounds

Make groups of compounds:

Na2O, HCl, CO2, Na2O2, Ca(OH)2, KClO, HCN, HNO2,

H2S, H2O2, BaO2, PbO2, H2SO3, KOH, MgSO4, NaF,

NH4HCO3, HI, Al(OH)3, HIO4, CdS, MgO2, NaH2PO4

? oxides hydroxides peroxides acids salts