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) Name something that isn't matter: _______________ Thanx to http://abyss.uoregon.edu/~js/images/states_of_matter.gif

Draw each phase in the box:

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

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

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

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 protons Mass number = # of protons + # of neutrons Atomic 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 neutral the # of protons = # of electrons How do you find the # of neutrons? # of neutrons = mass number -# of protons

Example…. Ni How many protons?_____ electrons?____ neutrons?____ +2 +1 +3 +4 Oxidation number 28 How many protons?_____ electrons?____ neutrons?____ Ni Nickel 58.71 mass 2 8 16 2

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 Nitrogen Gold Silver Lead Iron 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 Ex Atom p+ e- n0 Atomic mass 12C 6 12 14C 8 14 238U 92 146 238 235U 143 235