UNIT 3
Metals, Non-metals,
Metalloids Lab
Activity
• Use paper strips with element properties to create
your own periodic table.
• How did you arrange your table?
• What trends do you see?
• Use the element key to compare your layout with the
real periodic table.
• What similarities do you see?
• What differences do you see?
• Then rearrange your elements so they match the real
periodic table.
• Compare data for elements in the same group (column).
Melting
• Some attractive forces holding the particles together are
broken and particles move freely around each other but are
still close together. The stronger these forces are, the more
energy is needed to overcome them and the higher the
melting temperature.
Boiling
• The remaining attractive forces are broken so the particles
can move freely and far apart. The stronger the attractive
forces are, the more energy is needed to overcome them and
the higher the boiling temperature.
Period Table
Arrangement
Russian Chemist
Dmitri Mendeleev
Mendeleev’s table as published in 1869, with
many gaps and uncertainties
The physical and chemical properties
of the elements are periodic functions
of their atomic numbers.
Elements in the same group have
similar properties.
Each Group shares many properties such as
boiling point, melting point, conductivity, density.
• Alkali Metals form alkaline solutions when reacted with water.
• Alkaline Earth Metals - "Earth" was the alchemists term for the oxides
of alkaline earth metals.
• Transition metals – Can have valence electrons in a shell other than
the outer shell.
• Post-Transition metals – Lower melting and boiling points. Al, Sn, Pb
• Metaloids – Can exhibit properties of both metals and non-metals
• Halogen means “salt former”.
• Noble Gases - called "noble" because they rarely bond with other
elements.
ELECTRONS
What is an electron and how
does it behave?
Crest
Wavelength
Amplitude
Origin
Trough
Parts of a wave
What do you think is causing the
images in the next 4 slides?
Discuss with a neighbor.
Electrons shot one at a time – 100 Electrons
Electrons shot one at a time – 3,000 Electrons
Electrons shot one at a time – 20,000 Electrons
Electrons shot one at a time – 700,000 Electrons
Single slit - Classical Particles
Single Slit - Waves
Double Slit – Classical Particles
Double Slit - Light
Double Slit Experiment
Are electrons particles or waves?
Double Slit
Electrons
form a
diffraction
pattern just
like light.
Electrons shot one at a time – 100 Electrons
Electrons shot one at a time – 3,000 Electrons
Electrons shot one at a time – 20,000 Electrons
Electrons shot one at a time – 700,000 Electrons
Okay, so are electrons waves
or particles?
Quantum particles (like electrons)
behave as both particles and
waves.
What would happen if you do the same
experiment and record which electron
goes through each slit?
Double Slit – Electrons NOT Recorded
Double Slit – Electrons Recorded
Disconnect the Recorder but leave the detectors on.
Leave Recorder on but pull the tape out.
Turn everything back on.
It’s like they know they are being watched.
Video – You Tube
• Video – Dr. Quantum – Double Slit Experiment
DeBroglie’s Theory
Standing Wave
Rope
What does “quantum” mean?
A quantum is a distinct quantity of energy.
Energy being absorbed or emitted from
electrons happens only in particular quanta.
DeBroglie’s Theory
Complete “standing” waves only are
allowed – (“Quantized”)
How does this affect how the electron orbits
the nucleus?
Example on board
Draw wave orbitals standing and destructive
Calculate the hydrogen electron wavelength
DeBroglie’s Theory
Video – You Tube
• Video – How does the electron move around the atom?
• Video – Is the electron a wave or a particle?
• St. Mary’s Physics Online
Activity
• Cut out different numbers of wavelengths; 1, 2, 3, 4, 5.
• Demonstrate how the electron would create a wave around the
nucleus.
• Demonstrate different energy levels using the same method.