The document discusses the classification and properties of chemical elements. It defines the simplest classification as metals and non-metals based on appearance and physical properties. Metals are opaque, have metallic brightness, conduct heat and electricity well, and are malleable and ductile. Non-metals do not have metallic shine and are poor conductors of heat and electricity and not malleable or ductile. The document also discusses Mendeleev's periodic table, atomic mass, groups and periods in the periodic table, properties of representative groups of elements like alkali metals, alkaline earth metals, halogens and noble gases. It defines ionic and covalent bonds based on sharing or transfer of electrons.

1. THE CHEMICAL
ELEMENTS 3º
ESO
SERGIO SALOBREÑA
LUCENA
FUENGIROLA

2. ELEMENTS CLASIFICATION
THE CLASSIFICATION OF THE ELEMENTS IN METALS AND NON-
METALS IS THE SIMPLEST, AS IT APPLIES AS A CLASSIFICATION
CRITERIA ITS APPEARANCE AND SOME PHYSICAL PROPERTIES.
• METALS: THEY ARE OPAQUE AND HAVE METALLIC BRIGHTNESS.
DRIVE HEAT AND ELECTRICITY WELL. THEY ARE MALLEABLE (IT CAN
BE DECOMPOSED IN THIN SHEETS) AND DUCTILE (IT CAN BE
STRETCHED BY FORMING WIRES). ELEVATED POINTS OF FUSION
AND EBULLITION. EXAMPLES: IRON, COPPER, ZINC, TIN, GOLD ...
• NON-METALS: DO NOT HAVE METAL SHINE. BAD CONDUCTORS OF
HEAT AND ELECTRICITY. THEY ARE NOT MALEABLE OR DUCTILE.
VERY LOW FUSION AND EBULLITION POINTS. EXAMPLES:
HYDROGEN, OXYGEN, CHLORINE, BROMINE, SULFUR, FLUORINE,
NEON, CARBON, ETC.

3. EXERCISES
1. WHAT IS THE SIMPLEST CLASIFICATION OF ELEMENTS?
2. WHAT DOES DUCTILE MEAN? AND MALLEABLE?.
3. WRITE THREE PROPERTIES OF METALS.
4. WRITE THREE PROPERTIES OF NON-METALS.
5. WHICH OF THE FOLLOWING DATA BELONGS TO GOLD? AND THE PHOSPHORUS?
A) POINT OF FUSION= 1064 ºc B) POINT OF FUSION= 44,2 ºC
C) IT CAN´T BE DECOMPOSED IN THIN SHEETS. D) POINT OF EBULLITION= 280ºC
E) IT CAN BE STRECHED BY FORMING WIRES. F) POINT OF EBULLITION= 2856ºC
G) IT IS A BAD CONDUCTOR OF HEAT. H) IT HAS METALLIC BRIGHTNESS

4. FIRST PERIODIC CLASIFICATIONS
IN 1869, D. MENDELEIEV DISPOSE OF THE 63 CHEMICAL ELEMENTS
KNOWN IN THAT TIME IN GROWTH ORDER ACCORDING TO THEIR
ATOMIC MASSES, AND FOUND THAT THOSE WHO HAD SIMILAR
PROPERTIES WERE LOCATED IN THE SAME HORIZONTAL ROW.

5. THE ATOMIC MASS
THE ATOMIC MASS OF AN ELEMENT IS THE MASS OF AN ATOM OF
THAT ELEMENT. HOWEVER, IT DOES NOT BE EXPRESSED A LOT OF
THIS MEASURE TO BE VERY SMALL. FOR EXAMPLE: THE MASS OF A
HYDROGEN ATOM IS AROUND 10-27 Kg.
USUALLY IS USED THE RELATIVE ATOMIC MASS THAT IS THE MASS
OF AN ATOM COMPARED TO THE MASS OF THE TWELVE PART OF
THE ATOM OF C12. IT IS AN ADIMENSIONAL UNIT DENOMINATED
ATOMIC MASS UNIT THAT IS THE TWELVE PART OF THE MASS OF AN
ATOM OF C12 (u.m.a.).
THE ATOMIC RELATIVE MASS OF AN ELEMENT DOES NOT BE A
WHOLE NUMBER, BECAUSE MOST ELEMENTS HAVE SEVERAL
ISOTOPES IN NATURE IN DIFFERENT PERCENTAGES.

6. LA MASA ATÓMICA
LA MASA ATÓMICA RELATIVA

7. EXERCISES
1. WHO PERFORMED THE FIRST PERIODIC TABLE OF THE ELEMENTS? WHAT
CRITERIA DID HE USE TO CLASSIFY THEM?
2. WHAT IS THE ATOMIC MASS OF AN ELEMENT? AND THE RELATIVE ATOMIC
MASS OF AN ELEMENT? .
3. WHAT DOES U.M.A. MEAN? WHATT IT IS?.
4. CALCULATES THE ATOMIC RELATIVE MASS OF THE LITHIUM KNOWING
THAT IN NATURAL CONDITION THIS ELEMENT CONTAINS A 7.42% ISOTOPE
OF RELATIVE ATOMIC MASS 6, AND A 92.58% OF RELATIVE ATOMIC MASS
ISOTOPE 7.

8. CURRENT CLASSIFICATION OF THE
ELEMENTS
THE CURRENT PERIODIC TABLE ORGANIZES 118 ELEMENTS, OF WHICH 30
HAVE BEEN OBTAINED ARTIFICIALLY IN THE LAST DECADES.
THESE ELEMENTS ARE PLACED IN GROWING ORDER ACCORDING TO THEIR
ATOMIC NUMBER GROUPED BY GROUPS AND PERIODS.
• GROUP: IS EACH OF THE VERTICAL COLUMNS OF THE PERIODIC TABLE. THE
ELEMENTS OF THE SAME GROUP HAVE THE SAME NUMBER OF VALENCE
ELECTRONS, THEREFORE THEY SHARE SIMILAR CHEMICAL PROPERTIES.
• PERIOD: EACH OF THE HORIZONTAL ROWS OF THE PERIODIC TABLE. THE
ELEMENTS OF THE SAME PERIOD HAVE THE SAME NUMBER OF ELECTRONIC
LEVELS.
THE ELEMENTS WITH ATOMIC NUMBER FROM 58 TO 71 (LANTANIDOS) AND
FROM 90 TO 103 (ACTÍNIDOS) ARE SITUATED IN TWO ROWS OUTSIDE THE
TABLE.

9. METALS AND NON-METALS IN THE PERIODIC TABLE
WITHIN THE SAME PERIOD METALLIC PROPERTIES INCREASE AS WE MOVE
TO THE LEFT.
WITHIN THE SAME GROUP, METALLIC PROPERTIES INCREASE AS WE GO
DOWN ON THE TABLE.

10. EXERCISES
1. HOW MANY ELEMENTS ARE IN THE CURRENT PERIODIC TABLE?
2. DEFINE PERIOD AND GROUP.
3. WHAT DOES THE CURRENT CLASSIFICATION OF THE ELEMENTS OF
MENDELEIEV CLASSIFICATION DIFFER FROM?
4. TRUE OR FALSE:
A) CHLORINE HAS MORE METAL CHARACTER THAN SODIUM.
B) THE IODINE HAS MORE METAL CHARACTER THAN FLUOR.
C) SODIUM HAS MORE METAL CHARACTER THAN MAGNESIUM.
D) CALCIUM HAS MORE METAL CHARACTER THAN MAGNESIUM.

11. GROUP 1: THE ALKALINE ELEMENTS
THE ALKALINE ELEMENTS ARE METALS, EXCEPT THE HYDROGEN. THEIR
ELECTRONIC CONFIGURATION WILL ALWAYS PRESENT A SINGLE ELECTRON
IN ITS LAST LAYER, SO THAT THEY WILL HAVE VALENCE +1. TO ACHIEVE
GREATER STABILITY, THEY TEND TO LOSE THIS ELECTRON GIVING PLACE TO
CATIONS (IONS WITH POSITIVE CHARGE). THE ALKALINE ELEMENTS ARE: H,
Li, Na, K, Rb, Cs and Fr.

12. GRUPO 2: THE ALKALINE EARTH ELEMENTS
THE ALKALINE EARTH ELEMENTS ARE LESS REACTIVE METALS THAN THE
ALKALINE METALS. THEY ARE CHARACTERIZED BECAUSE THEY PRESENT 2
ELECTRONS IN THEIR LAST LAYER, SO THEY WILL HAVE VALENCE +2. TO
ACHIEVE GREATER STABILITY EASILY LOSE THESE TWO ELECTRONS, GIVING
PLACE TO CATIONS WITH CHARGE +2. ALKALINE EARTH ELEMENTS ARE: Be,
Mg, Ca, Sr, Ba AND Ra.

13. GROUP 18: THE NOBLE GASES
THE NOBLE GASES. THEY ARE NOT METALS THAT HAVE A LITTLE TENDENCY
TO COMBINE WITH OTHER ELEMENTS, DUE TO THEIR LAST LAYER IS
COMPLETED AND THEY ARE VERY STABLE. FOR THIS REASON THEY ARE IN
THE FORM OF ISOLATED ATOMS IN NATURE, THING THAT DOES NOT HAPPEN
WITH THE ALKALINES OR ALKALINE EARTH ELEMENTS. NOBLE GASES ARE:
He, Ne, Ar, Kr, Xe, Rn.

14. GROUP 17: THE HALOGEN ELEMENTS
THE HALOGEN ARE NON-METALS THAT TEND TO CONNECT WITH OTHER
ELEMENTS (THEY ARE VERY REACTIVE). THIS IS DUE TO ELECTRONIC
CONFIGURATION LACK AN ELECTRON TO COMPLETE THEIR LAST
LAYER. THEY HAVE TRENDS TO WIN AN ELECTRON, GIVING PLACE TO
NEGATIVE IONS (ANIONS) AND THEIR VALENCE IS
-1. HALOGEN ELEMENTS ARE: F, Cl, Br, I, At.

15. REPRESENTATIVE AND TRANSITIONAL ELEMENTS
THE REPRESENTATIVE ELEMENTS ARE THOSE THAT BELONG TO GROUPS 1,2
AND FROM 13 TO 18. ARE CHARACTERIZED BECAUSE IN NEUTRAL STATE
ONLY PRESENT ELECTRONIC LAYERS S AND P.
THE ELEMENTS OF TRANSITION ARE THOSE LOCATED IN THE CENTRAL PART
OF THE PERIODIC TABLE (GROUPS FROM 3 TO 12), WHOSE MAIN
CHARACTERISTIC IS THE PRESENCE IN ITS NEUTRAL STATE OF ORBITAL D.

16. EXERCISES
1. WHAT CHARACTERIZES THE ALKALINE ELEMENTS?
2. WRITE THE ALKALINE EARTH ELEMENTS. WHAT IS THEIR VALENCE?
3. WHY NOBLE GASES DO NOT FORM IONS IN NATURE?
4. WHY THE HALOGEN ELEMENTS TEND TO FORM NEGATIVE IONS?
5. DEFINE REPRESENTATIVE AND TRANSITIONAL ELEMENTS.

17. THE CHEMICAL LINK
WE CAN DEFINE CHEMICAL LINK AS AN ATTRACTION OF ELECTROSTATIC
TYPE BETWEEN TWO OR MORE ATOMS THAT ALLOWS THEM TO ACHIEVE
STABILITY.
THE HYDROGEN ATOM HAS ONLY 1 ELECTRON IN ITS LAST LAYER, BUT IF
TWO ATOMS OF HYDROGEN ARE APPROXIMATE THE SUFFICIENT CAN LINK
ITS ELECTRONIC LAYERS AND SHARE THEIR 2 e-. SO, BOTH REACH THE
STABILITY THAT PROVIDES HAVING THE LAST FULL LAYER.

18. TYPES OF CHEMICAL LINKS
IF IT HAPPENS IN THE HYDROGEN ATOM, THE LINK IS PRODUCED BY SHARING
ELECTRONS IS A COVALENT LINK. EXAMPLES OF THIS TYPE OF LINKS ARE
THE DIATOMIC MOLECULES AS OXYGEN (O2), NITROGEN (N2), CHLORINE (Cl2),
BROMINE (Br2) OR FLUOR (F2). THE COVALENT LINK IS REPRESENTED WITH
THE F-F SYMBOL (-).

19. FORMATION OF COVALENT CRYSTALS
THE CARBON ATOM HAS 4 e- IN ITS LAST LAYER. TO COMPLETE THE LAST
LAYER AND ACHIEVE STABILITY, IT NEEDS TO SHARE THEM WITH OTHER 4
ATOMS OF CARBON, THAT IS, FORMING 4 COVALENT LINKS. IN THIS
PROCESS, IT GIVES PLACE TO A CRYSTAL, A SOLID WHOSE PARTICLES ARE
ORDERED ACCORDING TO A PATTERN THAT IS REPEATED CONSTANTLY. THE
CARBON, ACCORDING TO THE SPACE PATTERN THAT FOLLOWS, CAN BE
FOUND IN NATURE IN TWO VARIETIES:
• DIAMOND: EACH ATOM OF CARBON IS LINKED TO OTHER FOUR CARBON
ATOMS ON A SAME PLANE. AS THERE ARE NO FREE ELECTRONS, IT DOES
NOT DRIVE THE ELECTRICAL CURRENT. IT IS A VERY STABLE NETWORK THAT
MAKES IT A VERY HARD SOLID, WITH HIGH POINTS OF FUSION AND
EBULLITION.
• GRAPHITE: EACH ATOM OF CARBON IS LINKED TO OTHER THREE ATOMS OF
CARBON ON A SAME PLANE, AND IN ADJACENT PLANS TO A FOURTH. THIS
LAST UNION IS MORE WEAK, SO THAT GRAPHITE LEADS THE ELECTRICITY
AND IS SOFT TO THE TOUCH.

20. EJERCICIOS
PÁGINA 53 EJERCICIO 7.
PÁGINA 54 EJERCICIOS 8,9,10.

21. TYPES OF CHEMICAL LINKS
MOST OF THE METALS HAVE 1,2 OR 3 e- IN THEIR LAST LAYER. IN A METALLIC
CRYSTAL, THE ATOMS THAT COMPOSE IT ARE POSITIVE IONS THAT HAVE
LOST THOSE EXTERNAL ELECTRONS, WHICH DO NOT BELONG TO A
CONCRETE ATOM (THEY ARE SAYED TO BE DELOCALIZED), MOVING
BETWEEN THE IONS OF THE CRYSTAL NETWORK.
WHEN THE ELECTRONS CAN BE MOVED WITH GREAT FREEDOM, METALS ARE
GOOD CONDUCTORS OF ELECTRICITY.
SO WE CAN DEFINE THE METALLIC LINK LIKE THAT ESTABLISHED BETWEEN A
GREAT NUMBER OF CATIONS THAT ARE KEPT UNITED BY A CLOUD OF
ELECTRONS.

22. EJERCICIOS
PÁGINA 53 EJERCICIO 7.
PÁGINA 54 EJERCICIOS 8,9,10.

23. EXERCISES
1. DEFINE: CHEMICAL LINK, COVALENT LINK AND METALLIC LINK.
2. HOW MANY ATOMS OF CARBON ARE UNITED TO EACH ATOM OF CARBON IN
THE DIAMOND AND HOW MANY ARE IN THE GRAPHITE?
3. HOW MANY ATOMS OF CARBON ARE UNITED ON THE SAME PLANE FOR
EVERY CARBON ATOM OF THE DIAMOND AND HOW MANY ARE AT THE SAME
PLANE IN THE GRAPHITE?
4. THE TERM A SEA OF ELECTRONS WOULD YOU RELATE TO WHAT TYPE OF
LINK?