Learn about the periodic table, and the chemical bonds

1. Periodic table
How is matter organized
Humanitas Bilingual School
2nd ESO
Physics and Chemistry

2. Previous ideas
• 2500 years ago: four elements(soil, fire, water, air)
• DALTON ATOMIC THEORY (1808)
• Matter made up of atoms, indivisible and indestructible.
• There are different types of atoms with different masses and
properties.
• Each Chemical element has a different type of atom.
• Chemical compounds are made of atoms of different elements.
• 118 ELEMENTS: NATURAL ELEMENTS(92) AND ARTIFICIAL
ELEMENTS(26)
• Chemical symbol: one or two letters. Same in all languages
• Fe, N, H, S, Au, Ca, Na, K, C, O, Cl, Ni…..
• More than 100 millions Compounds
• Chemical Formula.

3. PERIODIC TABLE
History: first was published by the Russian scientist Dimitri
Mendeleiev in 1869
• Double criteria (lately changed)
• Mass order (now is atomic number order)
• Colums by their chemical properties.
ORGANIZATION
PERIODS: Horizontal rows (7)
GROUPS: Vertical columns(18 )
Elements of the same group have the same number of
electrons in the last orbital, so they have similar properties.
The elements are in order according to the increasing
atomic number (number of protons)

4. Link to the periodic table
periods
groups

5. Extended
periodic table

6. Organization of groups(columns)
GROUP 1: ALKALI METALS ALCALINOS
GRUPO 2: ALKALI EARTH METALS ALCALINOTÉRREOS
GRUPO 3 AL 12: TRANSITION METALS METALES DE TRANSICIÓN
GROUP 13: BORON FAMILY GRUPO DEL BORO
GROUP 14: CARBON FAMILY GRUPO DEL CARBONO
GROUP 15: NITROGEN FAMILY GRUPO DEL NITRÓGENO
GROUP 16: OXYGEN FAMILY GRUPO DEL OXÍGENO
GRUPO 17: HALOGENS HALÓGENOS
GRUPO 18: NOBLE GASES GASES NOBLES.
RARE EARTH METALS TIERRAS RARAS

8. NAME OF THE ELEMENTS
• Greek or Latin (those known from long time
ago)
• Named after some characteristics.
• Named after the home country of the
scientist or the name of scientists.
• What would be the origin of these elements?
Pb Hg Cl Br Po Es
Lead Mercury Chlorine Bromine Polonium Einstenium
Plomo Mercurio Cloro Bromo Polonio Einstenio

9. Other examples of names.
• MITHOLOGY: helium, titanium, uranium, neptunium,
plutonium.
• PLACES: germanium, polonium, francium
• PROPERTIES OF THE ELEMENT: beryllium, chlorine, iodine
• What is their chemical symbol? And the atomic number?

10. Main blocks and characteristics
• Metals:
• They tend to lose electrons to become stable.
• They tend to form positive ions.
• They are good thermal and electrical conductors.
• 80% of the periodic table.
• Non-metals:
• They tend o gain electrons to become stable.
• They tend to form negative ions.
• They are thermal and electrical insulators.
• 9% of the known elements are non-metals.
• Noble gases
• Don’t lose or gain electrons= they are already stable.
• Don’t tend to form ions.
• They are gaseous, even at very low temperatures.
• They don’t combine with other elements or with themselves
• 5% of the elements
• Semimetals: borderline between metals and non-metals. Semiconductors, similar
to both. 6%.

13. Valence electrons
• Valence shell is the outermost layer with electrons.
• Valence electrons is the number of electrons of the valence
shell.

14. Oxidation number
• Basically is the number of electrons that they need to gain or
lose to become stable.
• They have a negative oxidation number if they need to gain
electrons, because electrons have negative charge)
• They have a negative oxidation number if they have to lose
electrons.
• Atoms can have different oxidation numbers depending on the
elements they combine with.

15. Some oxidation numbers

16. Types of chemical bonds
• Atoms of most Elements tend to create bonds with other
atoms.
• http://concurso.cnice.mec.es/cnice2005/93_iniciacion_interac
tiva_materia/curso/materiales/enlaces/enlaces1.htm
• Metal + nonmetal = ionic bond
• Nonmetal + nonmetal = covalent bond
• Metal + metal = metallic bond

17. Ionic bond
• Ionic bond: Involves a transfer of an electron, so one atom gains an
electron while one atom loses an electron. One of the resulting ions
carries a negative charge (anion), and the other ion carries a
positive charge (cation). Because opposite charges attract, the
atoms bond together to form clusters.

18. Covalent bond
• The most common bond in organic molecules, a covalent
bond involves the sharing of electrons between two atoms.
The pair of shared electrons forms a new orbit that extends
around the nuclei of both atoms, producing a molecule. There
are two secondary types of covalent bonds that are relevant
to biology — polar bonds and hydrogen bonds.
• Molecules
video

19. Metallic bond
• In metallic bonding, which occurs in metals (either a pure
metal or an alloy of two or more metals), the valence (outer
shell) electrons are donated to a “sea of electrons.”
• Metalic clusters