Transcript Chemistry 100 - University of Illinois at Urbana–Champaign

Clicker #1
How many of the following statements about atomic
theory are still believed to be true?
I.
All atoms of the same element are identical.
II. Negatively charged particles are embedded in a
positively charged cloud throughout the atom.
III. As verified by Rutherford, only positively
charged particles called protons are found inside
the nucleus.
IV. J.J. Thomson provided the first experimental
support for the atom.
A) 0
B) 1
C) 2
D) 3
E) 4
Clicker #2
Why does the pickle (the system) give off light? Choose
the best answer.
A) If you run electricity through anything, it will give
off light.
B) When protons are in an excited state due to
electricity, they glow.
C) The pickle contains sodium. The electricity is
causing the neutrons inside sodium to move across
between the two forks and thus make it glow.
D) Energy was put into the pickle (by electricity) so it’s
returning back to a lower energy state by releasing
light.
Clicker #3
When an electron is excited in an atom or ion
A) the electron moves further from the nucleus.
B) only specific quantities of energy are released in
order for the electron to return to its ground state.
C) white light is never observed when the electron
returns to its ground state.
D) the electron is only excited to certain energy levels.
E) All of the above statements are true when an
electron is excited.