Compounds/Mixture/Atomic Model

1. COMPOUNDS
Two or more elements are combined
chemically through a chemical
reaction.

2. Compounds are govern by the
law of definite proportion
proposed by Joseph Proust in
1799.
This states that a pure compound
always consist of the same
elements combined in the same
proportion by mass.

3. Water is always
formed by the
elements of
hydrogen and
oxygen in the
proportion 11.9%
hydrogen and
88.81% oxygen

4. A chemical formula is used as a
quick way to show the
composition of compounds.
Letters, numbers, and solid are
used to represent elements and
the number of elements in each
compound.
H2O- water
NaCl- salt
C12H22O11-sugar

5. Compounds can be classified into acids,
bases, and salts. To be able to
distinguish one from the other, you need
to use indicators.
Indicators- are substances whose color
are affected by acids and bases.
An example is the litmus paper.
Acid change a blue litmus paper to red.
Base change a red litmus paper to blue.
Salt do not affect the indicators

7. COMPOUNDS IN OUR DAILY ACTIVITIES
 Shampoo
 Conditioner
 Bath soap
 Vinegar or acetic acid
 Vetsin or monosodium glutamate
 Salt or sodium chloride
 Muriatic acid or hydrochloric acid
 There are some acid and bases that are
corrosive due to their acidity and basicity.

9. MIXTURES
An element or a compound is a pure
substance. All other kind of matter is
mixture. Mixture are composed of two
or more substances that are mixed
together physically.

11. Heterogeneous
mixture is not
uniformly
mixed

12. Homogeneous
mixture –there is
the same
proportion of
components
throughout the
mixture
It is also called
solution.

13. TYPES OF MIXTURES

14. ATOMIC MODELS

15. DALTON’S ATOMIC THEORY
(THE SOLID SPHERE MODEL)
John Dalton(1766-1844), an English
physicist and chemist, proposed his
atomic theory of matter in 1803. Hi
pictured atom as solid, indestructible
sphere with a mass that is like a
billiard ball.

16. JOSEPH JOHN THOMSON
(THE RAISIN BUN MODEL)
 J.J. Thomson (1856-1940)-, a British physicist, was
able to discover negatively charged particles known
electron using cathode ray tube.
It may also be similar to a cookie and chips in it._

17. ERNEST RUTHERFORD
(NUCLEAR MODEL OF AN ATOM)
Rutherford’s atomic model bears a
resemblance to a miniature solar
system, with positively charged
nucleus at the center, and the
electron revolving around the nucleus.
Due to discovery of nucleus his work
also known as Nuclear Model of an
Atom.

19. NEILS BOHR
(PLANETARY MODEL OF AN ATOM)

21. SUBATOMIC PARTICLES
Atoms are best described through
different atomic models.
Atoms are primarily made of three
sub-particles-proton, electron, and
neutron

23. ATOMIC NUMBER AND MASS
Ion- is called to a charged particles
Cation- the ion with positive charge
formed when electron is removed
from an atom.
Anion-the ion with negative charge, is
formed when the electron is added to
an atom.

24.  Atomic Number- “Numeric Identity “of the
Element.
 distinctive number of protons and also
represents the number of electrons.

25. Mass number- the mass of an
atom is based on the weight of
protons and neutrons in the
nucleus.
Isotopes- are atoms in the same
element with the atomic number
but differ in atomic mass
Nuclide- an atom of a specific
isotope

26. For neutral atom,
Number of protons = number of electron=
atomic number(Z)
Mass number (A) = number of Protons +
Number of neutrons
Number of neutrons = atomic number
(Z) – mass number

28.  Practice exercise
 Page 271