4. Matter- Atoms, Elements and Compounds… and You!!
Thanx to L. DaVinci

5. 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)
Name something that isn't matter: _______________
Thanx to

6. Draw each phase in the box:

7. How is a solid different from a liquid or gas or plasma? _____________

8. Atomic nucleus contains protons (p+) and neutrons (n0)
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

9. Atomic Models Dalton (1803)- first atomic theory; solid sphere
J.J. Thompson (1897)- plum pudding model;
Even distribution of + and – charges; discovered
the 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

10. 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!

11. More Atom Fun… Atomic number= # of protons Mass number = # of protons
+ # of neutrons
Atomic mass= average mass of one atom (approx. equals the #p+ and n0)

12. Even More… Elements are neutral the # of protons = # of electrons
How do you find the # of neutrons?
# of neutrons = mass number
-# of protons

13. Example…. Ni How many protons?_____ electrons?____ neutrons?____+2 +1 +3 +4
Oxidation number 28
How many protons?_____
electrons?____
neutrons?____ Ni
Nickel
58.71
mass

14. 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!

15. Chemical Symbols Give the symbol for each element below:
Carbon Helium Nitrogen
Gold Silver Lead
Iron Potassium Neon

16. 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 Ex
Atom p+ e- n0
Atomic mass
12C 6 12
14C 8 14
238U 92
146
238
235U
143
235