Making Models of Atoms and Molecules

1) Has anyone ever really SEEN an atom? Not with the naked eye, of course! Fancy machines like this scanning tunneling microscope allow us to see evidence of their existence. How do we know they exist?

2) Why are models helpful? They help us visualize things we can’t see. Some models show us very small things (like atoms ) up close while other models help us see very BIG things (like the solar system ) all at one time.

3) How many different subatomic particles does an atom have? Three: proton (+) neutron (0) electron (-)

4) Where are these subatomic particles located in the atom? proton - in the nucleus neutron - in the nucleus next to the protons electron - speeding around in the electron cloud

5) Which of the subatomic particles (if any) move about? The electrons!

6) How can we use the periodic table to determine the number of protons in an atom? The number of protons = the atomic number. Every different type of atom (element) has a different atomic number. You can think of this as its personal ID number.

7) How can we use the periodic table to determine the number of electrons in an atom? Number of electrons = number of protons

8) How can we use the periodic table to determine the number of neutrons in an atom? Atomic mass – number of protons = number of neutrons ~ 96 (round off) = 54 neutrons

Let’s begin! Protons – yellow peas Neutrons – brown peas Electrons – sprinkles

Fill out your card and get it checked before you glue any parts. Name & Symbol of atom: _______________________________ ______ Atomic number: _________ Atomic mass (rounded off): ________ # of protons: __________ # of neutrons: ___________ # of electrons: __________ # of valence electrons: _________ Electron Configuration: ________________________________________ Student Name: ______________________________________________

What will our atoms look like?

What will our molecules look like?

We will be counting the atoms and the different elements in each molecule. The next slide will show you how to add the information to each box. Name of molecule: _____________________ Formula: _____________________________ # of Atoms=____ # of Elements=____ Compound? Yes or No? (See the next slide)

We will be counting the atoms and the different elements in each molecule. Add this info to each card as shown in red below. Name of molecule: _____________________ Formula: _____________________________ A=____ E=____ C- _______

water H2OH2O

carbon dioxide CO 2

oxygen O2O2 O O

ethanol C2H6OC2H6O

nitrogen N2N2

nitric acid HNO 3

ozone O3O3 O O O

chlorine dioxide ClO 2

hydrogen peroxide H2O2H2O2

ammonia NH 3

hydrogen H2H2

fluorine F2F2 F F

methane CH 4

nitroglycerin C3H5N3O9C3H5N3O9 Can you pick out the atoms?

oil of spearmint C 10 H 14 O Can you pick out the atoms?

glucose C 6 H 12 O 6

sucrose C 12 H 22 O 11 Each white sphere represents a hydrogen atom (black = carbon, red = oxygen)

The following are ionic compounds and they are not considered molecules (which have covalent bonds.)

magnesium fluoride MgF 2

baking soda NaHCO 3

potassium nitrate KNO 3 K N O O O

potassium chloride KCl

rust Fe 2 O 3 yields

salt NaCl

sodium hydroxide NaOH