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Matter- Atoms, Elements and
Compounds… and You!!
Thanx to L. DaVinci
First of all… What’sa Matter?
•Matter is anything that has mass and takes up space
•Everything in the observable universe is made of matter (as far as we know)
Thanx to http://abyss.uoregon.edu/~js/images/states_of_matter.gif
Name something that isn't matter: _______________
Draw each phase in the box:
How is a solid different from a liquid or gas or plasma? _____________
Atomic Structure:
Atomic nucleus contains protons (p+) and neutrons (n0)
-this makes up most of the atomic mass
electrons (e-) are outside nucleus; have very little mass
# of protons = # of electrons
If atoms are mostly empty space, how can they make up solid objects? Hmm
Atomic ModelsDalton (1803)- first atomic theory; solid sphere
J.J. Thompson (1897)- plum pudding model;Even distribution of + and – charges; discoveredthe electron!
Rutherford (1909)- planetary model; e- orbit a dense nucleus
Bohr (1913)- energy level model
Schrodinger (1927)- quantum mechanical Model; energy levels w uncertain orbits
Did you know…..If an electron weighed the same as a dime, a proton would weigh the same as a gallon of milk?
But…neutrons and protons have almost the same mass!
More Atom Fun…Atomic number= # of protonsMass number = # of protons
+ # of neutronsAtomic mass= average mass of one
atom (approx. equals the #p+ and n0)
http://mrbloch516.edublogs.org/files/2015/01/photo-oxygen-1l18wri.jpg
Even More…
Elements are neutralthe # of protons = # of electrons
How do you find the # of neutrons?
# of neutrons = mass number -# of protons
28
NiNickel58.71
2 8 16 2
+2
+1
+3
+4
Oxidation number
mass
How many protons?_____electrons?____ neutrons?____
Example….
Elements•Atoms make up elements•Elements are the simplest pure
substances (ex. Hydrogen, Helium, Oxygen); can’t be broken down by chemical means–92 naturally occurring; Earth’s crust is mostly Oxygen and Silicon
–The universe is mostly Hydrogen and Helium!
Chemical Symbols
•Give the symbol for each element below:
Carbon Helium NitrogenGold Silver LeadIron Potassium Neon
Isotopes (sound weird)
• An element always has the same # of p+ and e- but n0 may vary!– An element with a # of n0 outside the
norm is called an isotope– In this case, atomic # stays the same
BUT atomic mass changes
• ExAtom p+ e- n0 Atomic
mass12C 6 6 6 1214C 6 6 8 14238U 92 92 146 238235U 92 92 143 235