2. What is food service?
There are some basic principles in food and beverage service that a
waiter must know:
• When food is served by the waiter at the table from a platter
onto a guest plate, the service is done from the left.
• When food is pre-plated the service to the guest is usually
done from the right, though modern convention permits service
from the left also.
• All beverages are served from the right.
• Soups are served from the right unless it is poured by a waiter
from a large tureen into a soup cup in which case it is done from
the left of the guest.
• Ladies are always served first and the remaining guests
clockwise. Soiled plates should always be cleared from the table
from the right.
• Empty crockery and fresh cutlery are always served from the
right. Never reach across a Customer. Hence, when a guest is
3. HISTORY OF THE ATOM
460 BC Democritus develops the idea of atoms
he pounded up materials in his pestle and
mortar until he had reduced them to smaller
and smaller particles which he called
ATOMA
(greek for indivisible)
4. HISTORY OF THE ATOM
1808 John Dalton
suggested that all matter was made up of
tiny spheres that were able to bounce
around with perfect elasticity and called
them
ATOMS
5. HISTORY OF THE ATOM
1898 Joseph John Thompson
found that atoms could sometimes eject a
far smaller negative particle which he called
an
ELECTRON
6. HISTORY OF THE ATOM
1904
Thompson develops the idea that an
atom was made up of electrons
scattered unevenly within an elastic
sphere surrounded by a soup of
positive charge to balance the
electron's charge
PLUM PUDDING
like plums surrounded by
pudding.
MODEL
7. HISTORY OF THE ATOM
1910 Ernest Rutherford
oversaw Geiger and Marsden carrying out his
famous experiment.
they fired Helium nuclei at a piece of gold foil
which was only a few atoms thick.
they found that although most of them
passed through. About 1 in 10,000 hit
8. HISTORY OF THE ATOM
They found that while
most of the helium
gold foil
helium nuclei
nuclei passed through
the foil, a small number
were deflected and, to
their surprise, some
helium nuclei bounced
helium nuclei
straight back.
9. HISTORY OF THE ATOM
Rutherford’s new evidence allowed him to propose a more
detailed model with a central nucleus.
He suggested that the positive charge was all in a central
nucleus. With this holding the electrons in place by
electrical attraction
However, this was not the end of the story.
10. HISTORY OF THE ATOM
1913 Niels Bohr
studied under Rutherford at the Victoria
University in Manchester.
Bohr refined Rutherford's idea by adding
that the electrons were in orbits. Rather
like planets orbiting the sun. With each
orbit only able to contain a set number of
electrons.
11. Atomic Structure
Atoms are composed of 2 regions:
Nucleus: the center of the atom that contains the
mass of the atom
Electron cloud: region that surrounds the
nucleus that contains most of the space in the
atom
Nucleus
Electron
Cloud
15. What’s in the Nucleus?
The nucleus contains 2 of the 3
subatomic particles:
Protons: positively charged subatomic particles
Neutrons: neutrally charged subatomic particles
16. What’s in the Electron Cloud?
The 3rd subatomic particle resides
outside of the nucleus in the electron
cloud
Electron: the subatomic particle with a negative
charge and relatively no mass
18. How do the subatomic particles
balance each other?
In an atom:
The protons = the electrons
If 20 protons are present in an atom then 20
electrons are there to balance the overall
charge of the atom—atoms are neutral
The neutrons have no charge; therefore
they do not have to equal the number of
protons or electrons
19. How do we know the number of
subatomic particles in an atom?
Atomic number: this number indicates
the number of protons in an atom
Ex: Hydrogen’s atomic number is 1
So hydrogen has 1 proton
Ex: Carbon’s atomic number is 6
So carbon has 6 protons
**The number of protons identifies the
atom.
Ex. 2 protons = He, 29 protons = Cu
20. How do we know the number of
subatomic particles in an atom?
Mass number: the number of protons
and neutrons in the nucleus
Ex: hydrogen can have a mass of 3.
Since it has 1 proton it must have 2
neutrons
# of neutrons = mass # - atomic #
21. Determining the number of
protons and neutrons
Li has a mass number of 7 and an atomic
number of 3
Protons = 3 (same as atomic #)
Neutrons= 7-3 = 4 (mass # - atomic #)
Ne has a mass number of 20 and an atomic
number of 10
Protons = 10
Neutrons = 20 - 10= 10
22. What about the electrons?
The electrons are equal to the number of
protons
So e- = p = atomic #
Ex: He has a mass # of 4 and an atomic # of
2
p+ = 2
no = 2
e- = 2
23. Determine the number of
subatomic particles in the
following:
Cl has a mass # of 35 and an atomic # of 17
p+ = 17, no = 18, e- = 17
K has a mass # of 39 and an atomic # of 19
P+ = 19, no = 20 e- = 19
24. How exactly are the particles
arranged?
Bohr Model of the atom:
Reviewers think this could lead to misconceptions!
All of the
protons and
the neutrons
The 3rd ring
can hold
up to 18 e- The 1st ring can
The 4th ring hold up to 2 e-
and any after The 2nd ring can
can hold up hold up to 8 e-
to 32 e-
25. What does carbon look like?
Mass # = 12 atomic # = 6
6 p and 6 n live
in the nucleus
p+ = 6 no = 6 e- = 6
