View
220
Download
0
Category
Tags:
Preview:
Citation preview
Unit 2 – Lecture 3
Atomssmallest particle of an element that retains
its chemical propertiescomposed of subatomic particles
protons (p+), neutrons (n0), & electrons (e-)“sub-” = below, less than
Subatomic ParticlesTypes of Subatomic Particles[p+] – positively charged subatomic particle
found in the nucleus of an atomrelative mass = 1 amu [atomic mass unit]
[n0] – non-charged subatomic particle [neutral]found in the nucleus of an atomrelative mass = slightly larger than 1 amunew theories: [p+] + [e-] = [n0] ?
Subatomic Particles – cont’d[e-] – negatively charged subatomic particle
found outside of the nucleus in energy levels [aka e- clouds, e- shells, etc]
no relative mass[actual mass is 1/1936th of 1 amu…]
Quarks?theoretically = smaller particles that
make up (p+), (n0), & (e-)have their own branch of “theoretical
physics”
DiscussWhich subatomic particle is neutral?Which describes a single particle of an
element?Which subatomic particle is negative?Which subatomic particle may or may not
exist?Which is a single particle of a compound?Which subatomic particle is positive?
Elements
Elements – cont’dElements are found on the periodic table in
their natural, neutral statemeaning, they’re neutral = same # of p+ &
e -
Discuss - Oxygenatomic mass?number of protons?atomic number?number of electrons?chemical symbol?number of neutrons?
More PracticeAn atom with 4 protons and 6 neutrons
would:have a mass of…?have an atomic number of…?have … electrons typically?be which element?
Writing Elements - SilverWrite:Chemical SymbolMass Number at the
upper-left of the symbolAtomic Number at the
lower-left of the symbolCharge [if applicable] at the
upper-right hand corner
NOT ALL OF THESE ARE NECESSARYNOT ALL OF THESE ARE NECESSARY
Ag108
47
+4
Counting Particlesp+s = Atomic Number
[17]n0s = Atomic Mass – Atomic Number
[35-17 = 18]e-s = p+s
[17]
Cl3517
Counting Particles – cont’dif e-s differ
called ioncharge is different
more e-s [than normal] = more negative charge
less e-s [than normal] = more positive charge
Counting Particles – cont’dif n0s differ
called isotope“iso-” = equal/same
same chem & phys properties atomic mass on periodic table is average of
isotopes
if p+s differis a different element
Isotopes – Examples
Different Atoms, Same ElementAllotrope – different natural/physical forms of
an element“allo-” = other/differentEx. for Carbon: Graphite, Diamond,
Buckminsterfullerenes [buckyballs]…Ex. for Oxygen: [O2], Ozone [O3]
Allotropes of Carbona. diamondb. graphitec. lonsdaleited. buckyballs [C60 –
buckminsterfullerene]e. C540f. C70g. “amorphous” carbon
[not truly amorphous]h. single-walled
carbon nanotube / buckytube
Allotropes of Oxygen
Electron-Dot Modelsp+s & n0s exist in the nucleuse-s exist in electron/energy shells
around the nucleus“octet rule” - atoms will gain,
lose, or share e-s to become chemically stable [8 e-s in valence shell]valence shell = outer-most shell
e-s in valence shell = valence e-s
Electron-Dot Models
• Draw • Nucleus• Protons• Neutrons
Electron-Dot Models – cont’d
• Draw• Electrons
Electron Levels• *2*• up to 8…
DiscussAtoms are the smallest particle of
elements, compounds, homogeneous mixtures, heterogeneous mixtures
Which subatomic particle has a neutral charge?protons, neutrons, electrons, quarks
What is the dense center of an atom called?protium, nucleus, neutron core, core
DiscussWhich property discerns atoms from one
another?atomic mass, mass number,
atomic number, none of the above
Atomic Number is based on which property of atoms?# of protons, # of electrons,
# of neutrons, total # of particles
DiscussThe total number of nucleons is
atomic mass, atomic number, nucleon count, state of matter
Atoms of an element with different number of neutrons areallotropes, isotopes, megatopes,
gigatropes
Which subatomic particles are not included in calculating Atomic Mass?protons, neutrons, electrons, nucleons
DiscussHow many neutrons are in Oxygen-16, which
has an atomic number of 8? [# denotes mass]4, 6, 8, 10, 12, 14, 16
How many neutrons are in Oxygen-18, which has an atomic number of 8?4, 6, 8, 10, 12, 14, 16
Which subatomic particle has a positive charge?Protons, Neutrons, Electrons, Quarks
How many e-s fit in an atom’s first electron level?
HomeworkComplete - page 13 - # of Atoms in a Formula w/s
DO NOT COMPLETE GRAM FORMULA MASS w/s IN THE MIDDLE OF PAGE 13.
- BOTTOM of pg 13-top of 14 Parts of An Atom [CHART]
Recommended