Download Bell Ringer 10/03/2013 What does the atomic number represent? A

Bell Ringer
10/03/2013
What does the atomic number represent?
A: the # of protons
The # of (total) electrons
And/or the way the periodic table is
organized
Pages 91-102
Atomic
Dalton’s theory:
theory of *Each element is
matter
composed of extremely
small particles called
atoms
*All atoms of a given
element are identical, but
they differ from those of
any other element
*Atoms are neither created
nor destroyed in any
chemical reaction
*A given compound
always has the same
relative numbers and kinds
of atoms
Dalton
*Atomic theory of matter
(scientist) (see above)
*coined the word “atom”
Theory- tiny spheres
bounce around like hard
balls
Democrit Theory- all matter, the
us
stuff that makes up the
(scientist) world around us, is
actually composed of tiny,
invisible particles (coined
“atoma”)
Atom
- the smallest particle of an
element that retains the
chemical identity of that
element; electrically
neutral (protons and
electrons have the same
quantity); contains
protons, neutrons, and
electrons
Electron Negatively charged it is
found outside of the
nucleus
(Thomson founded)negative particles
(Millikan measured the
charge of an electron)
Thomson *Model- Plum Pudding
(scientist) Model
- Found negative particles
(electrons)
- thought negative
electrons were in a
positive sphere
**Test- Cathode Ray Tube
Radioacti - the spontaneous emission
vity
of radiation from an
element (discovered by
Becquerel)
Nucleus
Rutherfor
d
(scientist)
*Schrodi
nger
(scientist)
*Bohr
(scientist)
(Rutherford discovered)all of atom’s positive
charge is inside, as well as
most of its mass
Test- Gold Foil
Experiment- measured the
mass of an electron
- Discovered protons
*Model- positive center
with negative electrons on
outside
Model- Wave
Theory- electrons as
continuous moving and
cannot tell exact location;
small positively charged
nucleus
Theory- electrons were in
orbits based on energy
levels (moved around the
positive nucleus)
Evidence for theory- how
electrons absorb and emit
light
pages 91-102
Atomic theory of matter (all 4 bullet points p.92)
-Dalton (scientist)
-Democritus (scientist)
Atom
Law of Constant Composition
-Thomson (scientist)
Radioactivity
Nucleus
-Rutherford (scientist)
*Schrodinger (scientist)
*Bohr (scientist)
(*= teacher will supply notes for these scientists)
Exit Slip- p. 91-102
10/03/13
(answers only- unless you want to write the question)
1) Which scientist/philosopher proposed that all
matter is composed of tiny, invisible particles?
2) How many postulates (or bullet points) did Dalton’s
atomic theory of matter have?
3) Who studied electricity and named his findings
“positive” and “negative”?
4) What was the name of Thomson’s model called?
E.C. 5) Which scientist “measured” the charge of the
electron?