11/11/08
Post date: Nov 10, 2008 9:48:30 PM
Bell Activity: What is an atom?
Building blocks
Atom - the smallest unit of an element that still behaves like that element
made of protons, neutrons, and electrons
protons and neutrons at the center, make up the nucleus
electrons orbit around the nucleus
Periodic Table
Atomic number is number of protons
Atomic mass is protons + neutrons
Same number of electrons as protons
Draw the atoms of Magnesium, Iron, Aluminum, and Zinc to turn in during class.
Molecule - two or more atoms that are bonded together
Matter is classified as either an element, a compound, or a mixture
Elements - made of only one kind of atom
The types of building blocks we have
Marshmallows - different colors are different elements
The periodic table arranges elements by the properties of their atoms
Number represents number of protons
Mass is protons and neutrons, electrons have VERY little mass
As a class, we create a visual table of elements (drawing each atom)
Examples - Copper wire made of only copper atoms, aluminum foil made of only aluminum atoms
Social example - men or women
Compounds - made of two or more types of atoms
Marshmallows - multiple colors bonded together
Examples - water is hydrogen and oxygen, table salt is sodium and chlorine, sugar is hydrogen, oxygen, and carbon
We use chemical formulas to represent formulas
Use element symbol from periodic table
Use numbers to note how many of each atom we have bonded together
Social example - a couple
Mixtures - Elements and/or compounds are mixed together, but could be separated again
Marshmallows - multiple colors NOT bonded, or multiple different bonded molecules
Elements and compounds are pure substances, meaning their is a fixed ratio of components. Mixtures are not pure substances, meaning you could have any ratio of components in the mixture.
Compounds have 2 or more elements bonded together, and cannot be separated
The parts of mixtures are not bonded together, and can be separated
Can be solid in solid, liquid in liquid, gas in gas, or combinations.
Social example - non-couples in a room together, or couples in a room with other couples or with single people
In groups of 3-4, create another analogy for elements, compounds, and mixtures to share with the class