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 ArrangementRussian ChemistDmitri 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 asboiling 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?

Parts of a wave

Wavelength

AmplitudeOrigin

Crest

Trough

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 TheoryStanding WaveRope

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 TheoryComplete “standing” waves only are allowed – (“Quantized”)

How does this affect how the electron orbits the nucleus?

Example on boardDraw wave orbitals standing and destructiveCalculate 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.