No, you do not need to learn the complete periodic table right away. Focus on learning: - The names and symbols of the most common elements like H, He, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ca, etc. - The overall layout and organization of the periodic table. Pay attention to how elements are grouped based on their properties. - Key trends as you read across or down the periodic table, such as changes in atomic radius, electronegativity, metallic/non-metallic character. As you study chemistry concepts involving different elements, you will naturally learn more of the periodic table over time. But it's

1. MIXTURES Pure Substances
Matter surrounds us mainly
in the form of mixtures. Once we have
obtained pure
substances out of the
But we’ll have to do mixtures, we can go
something to obtain :
on studying this type
of substances to
classify and
characterize them.

2. MIXTURES Pure Substances

3. MIXTURES PURE SUBSTANCES
What’s MATTER?
Anything that has mass and occupies space.
HOW TO TELL A MIXTURE FROM A
PURE SUBSTANCE FROM THE
MACROSCOPIC POINT OF VIEW?

4. PURE SUBSTANCES
Only pure substances have fixed
physical properties under given
conditions.

5. MIXTURES
?
MACROSCOPICALLY HOMOGENEOUS
PURE SUBSTANCES We have to measure its properties

6. Pure substance: Mixture:
Fixed boiling point Unclear boiling point

7. Sometimes is easier
because we can
observe “two things”
from the macroscopic
point of view

8. MIXTURES
? MACROSCOPICALLY HETEROGENEOUS
BUT!
The problem is here ag
PURE SUBSTANCES

9. LET’S CHANGE OUR
POINT OF VIEW

10. MIXTURES PURE SUBSTANCES
Mixture: Made of Pure substance:
more than one kind Made of only one
of PARTICLE kind of PARTICLE

12. MIXTURE
Considered from the M1 point of
view, it is made out of more than
one type of particle
The composition of a mixture is VARIABLE.
Same samples contain different number of
each of the components o the mixture. It can
be recovered by putting the ingredients
together.
It is easy to separate.
It is easy to separate
because its components
maintain their properties.

13. MIXTURE COMPOUND

14. MIXTURE COMPOUND
Considered from the M1 point of Considered from the M1 point of view,
view, it is made out of more than it is made out of one type of particle.
But from the M2 point of view each
one type of particle
particle contains more than one type of
atom.
The composition of a mixture is VARIABLE. The composition of a
Same samples contain different number of
each of the components o the mixture. It can compound is fixed. We could
be recovered by putting the ingredients even give a formula for each
together.
compound (H2O, NH3).
It is easy to separate. It is difficult to separate.
It is easy to separate because its It is difficult to separate because, being
components maintain their properties a pure substance, we have to break the
and we can separate them without particle of the substance. After this
breaking the substances the mixture is process the initial substance is not
made out of. The initial mixture is normally recovered.
normally recovered when mixing again

15. MIXTURES Pure Substances

16. MIXTURES
HOMOGENEOUS HETEROGENEOUS

17. Heterogeneous Mixtures
• Heterogeneous mixture -A mixture in which
different materials can be distinguished
easily
Heterogeneous: A material which is not uniform at
all macroscopic levels and methods of observation.

18. Homogeneous Mixtures
• Homogeneous mixture two or more
gaseous, liquid, or solid substances blended
evenly throughout.
Homogeneous:
Uniform at all
macroscopic levels
and methods of
observation

19. MIXTURE
What does this mean?
How to consider this
variability in a
homogeneous mixture
Variable
composition

20. HETEROGENEOUS
(Even from the
MACROSCOPIC point of
view)
THE COMPOSITION
VARIES DEPENDING ON
THE PART OF THE
MIXTURE I CONSIDER

21. HOMOGENEUS
- From the MACROSCOPIC
point of view
HETEROGENEOUS
- From the MICROSCOPIC 1
point of view)
We know it contains more than one type of
particle. We also know that it does not have
fixed physical and chemical properties.

22. In this case, the
composition will not
depend on the part of the
mixture we consider!
If this is water with salt, both parts of the substance will
contain the same proportion of salt particles and water
particles
Then, What does VARIABLE COMPOSITION mean?

23. The composition of the
mixture can be easily changed
by adding more salt or more
water.
Every time you do this, you
obtain a mixture with a
different composition and
with different properties
(density, for instance)

24. On the contrary, water, as
pure substance, has a fixed
composition, a fixed
formula. (H2O)
But to undesrtand this fact
we have to consider pure
substances from the
MICROSCOPIC 2 point of view

25. MIXTURES Pure Substances
HOMOGENEOUS HETEROGENEOUS HOMOGENEOUS
>1 type of >1 type of 1 type of particle
particle particle
PHYSICAL
COMPOUND ELEMENT
Sieving
Evaporation Filtration
Distillation Decantation
Centrifugation
CHEMICAL
ELECTROLYSIS
….
MORE THAN 1 TYPE OF ATOM
1 TYPE OF ATOM
H20, CS2, PCl5 H2, S8, O3

26. Now the map
is complete!

27. MICROSCOPIC 2 POINT OF VIEW : ATOMS
.- Atoms is what the particles are made out of!
.- There can be different types of atoms in a
particle / molecule!
.- The unique way in which the atoms are
bonded give the particle / molecule its name
and properties

28. GLUCOSE MOLECULE
RED BALL : OXYGEN ATOM
GREY BALL : CARBON ATOM
WHITE BALL : HYDROGEN ATOM

29. GLUCOSE MOLECULE

30. GLUCOSE MOLECULE FORMULA
A way to simplify the formula of a molecule is to
write the type of atoms and its number this way:
C6H12O6
But to be a “glucose”
molecule the atoms must
be bonded this way.

31. Ar e t h e r e o t h e r wa y s
t o b o n d 6 c a r b o n a t o ms ,
12 h y d r o g e n a t o m s a n d 6
o x y g e n a t o ms ?
Ye s , t he r e a r e .

33. ASPIRIN MOLECULE

34. WATER MOLECULE
H20
This is how atoms bond in a water molecule

35. We will only deal with
shorthand formulas for
the different pure
substances.
The real 3D structure, why
atoms bond in this
particular way (and how)
is not to be discussed this
year.

36. JUST REMEMBER:
.- Atoms is what the particles are made out of!
.- There can be different types of atoms in a
particle / molecule!
.- The unique way in which the atoms are
bonded give the particle / molecule its name
and properties

37. AND HOW MANY DIFFERENT
ATOMS ARE THERE?

39. Each element has a name, a symbol and a
place in the periodic table.
The periodic table is the best way
to list the atoms of the different
elements.
Remember that an element is a pure
substance made out of one type of atom.

40. DISCOVERING THE ELEMENTS: 1730

41. DISCOVERING THE ELEMENTS: 1798

42. DISCOVERING THE ELEMENTS: 1870

43. DISCOVERING THE ELEMENTS: 1934

44. DISCOVERING THE ELEMENTS: 2011

45. And … how to learn the
names of the elements??
Not so difficult!. There’s even a song!!!

47. Try it again

48. Apart from the name:
Each element has a symbol. For two letter symbols use a
capital letter for the first one and a small letter for the second
(Ca, Sr, Ba, Ra, Sn, Sb, Sc, Ti, Mg, Mn). Use a capital letter
to write one letter symbols (C, S, O, F, H, N, K, B ...)
Every PURE chemical substance (element or compound) has a
formula that shows the type of atom and the number of each
type of atom present in a particle of the substance.
The formula does not give any clue about how the atoms
are arranged and bonded together.

49. NUMERICAL SUBSCRIPTS:
They must be subscripts and they must be
written following the symbol they refer to:
H2O: 2 atoms of hydrogen and
1 atom of oxygen.
There is no need to write “1” if there is only
one atom of this kind)

50. A group of atoms in brackets means that this group
of atoms is repeated in the molecule (or particle).
The subscript that follows the bracket informs us
about how many times this group is repeated.
Ca3(PO4)2
3 atoms of calcium.
2 * 1 = 2 atoms of phosphorus.
2 * 4 = 8 atoms of oxygen.

51. Do we have to learn the
complete periodic table ???????