Transcript PS 2.1

PS-2.1
Compare the subatomic particles of an atom
with regard to mass, location, and charge, and
explain how these particles affect the properties
of an atom (including identity, mass, volume,
and reactivity).
The atom is composed of subatomic particles
(protons, neutrons, and electrons) that affect the
properties of an atom.
Protons and neutrons have about the same
mass.
•1 Proton is approximately 1 a.m.u.
•1 Neutron is approximately 1 a.m.u.
One Atomic Mass Unit is
equal to 1/12th the mass of
one atom of Carbon-12.
The mass of an electron is much less than the
mass of protons and neutrons
•1 Electron is approximately 0.0005 a.m.u.
Protons have a positive charge; know that
neutrons have no charge.
The net charge of the nucleus is positive and
equal to the number of protons.
Electrons have a negative charge.
There is an attractive force between electrons
and protons
There is a repulsive force between electrons
and electrons, and between protons and protons
Atoms are neutrally charged because the
number of electrons is the same as the number of
protons.
Protons and neutrons are tightly bound in a
tiny nucleus.
The nucleus is located in the center of an electron
cloud.
The electron cloud is the space where electrons
are moving erratically in areas of space called
energy levels.
Energy levels are regions of space at increasing
distances from the nucleus.
Home Work
p. 549 #1-4