Transcript atoms ppt lecture - Mayfield Science

The Structure of
the Atom
1. The Atom
a. “the building blocks” of all matter
b. Particles that make up the atom:
1. Nucleus
a. “core” of the atom
b. 99.9 % of the mass
c. Yet the nucleus is nearly
100,000 times smaller than
the rest of the atom.
example: a bee
compared to a football
stadium.
d. Protons
1. Positive Charge
2. p+
3. mass of a proton = 1 amu
(atomic mass unit)
e. Neutrons
1. Neutral Charge
2. n
3. slightly more mass than
protons, but still
considered 1 amu.
2. Atomic Number
a. # of protons in the nucleus
b. Identifies the element
ex. H = 1
Mg = 12
c. Since + and - charges are
normally equal, it is also the
number of electrons.
3. Mass Number, Atomic Mass, & Isotopes
a. Mass Number = protons + neutrons
b. Atomic Mass is the average mass
of all existing isotopes of a given
element.
c. Isotopes
- Atoms of the same element
that have the same # of
protons, but a different #
neutrons.
How many neutrons
are in Carbon 12, 13,
and 14?
5. The Electron
a. 1/2000 the size of a proton or
neutron.
b. Negative charge
c. Electron Cloud- the space that
electrons are likely to be found.
Size of an Electron vs Proton
If an electron weighed the same as a dime,
a proton would weigh the same as a gallon of
milk.
Size of an Atom
If this were the proton in a hydrogen atom,
it would take a screen 1 mile across to display
the electron's orbit.