atomic structure ppt i stoe from my science teacher lol

2. What does the atom
look like according to
Dalton?

3. What does the atom
look like according to
Dalton?

4. Short activity

5. ▪ For many years, scientists have known that
matter and electric charge were related.
▪ When amber is rubbed with fur, or glass with
silk, positive and negative charges form
▪ They also know that electric current can also
decompose compounds into its elements.
▪ What is current made of?

6. ▪ Mid-1800s, scientists began to study electrical
discharge through

7. • Ray of energy that
travels in waves
• Stream of moving
particles
• J.J. Thomson

9. ▪ Concluded that the ray is composed of particles
that have mass
▪ Negatively-charge
▪ Though they have mass, it is very small
compared to the lightest atom known
(hydrogen).
▪ It was about 2000 times less massive.
▪ Electron

10. ▪ The electron was the first subatomic particle to
be discovered.
▪ The atomic model needed to be redeveloped.

12. ▪ Thomson, through the cathode ray tube, was
not able to determine the approximate mass of
the electron, but only its mass-charge ratio.
▪ Robert Millikan
▪ Oil drop experiment

14. ▪ Thomson, through the cathode ray tube, was
not able to determine the approximate mass of
the electron, but only its mass-charge ratio.
▪ Robert Millikan
▪ Oil drop experiment
▪ Charge:
▪ Mass:

15. • Ernest Rutherford
with Hans Geiger and
Ernest Marsden

20. ▪ The atom is mostly empty space.
▪ The atom has a very dense, positively charged
area, contrary to Thomson’s.
▪ The atomic model needs to be redeveloped.

22. ▪ Positively charged
nucleus and negatively
charged electrons: what
will happen?
▪ To counteract attractive
forces, Rutherford said
that electrons should
move in circular orbits.

23. ▪ Rutherford detected hydrogen nuclei when a
beam of alpha particles were shot into the air.

24. ▪ The nuclei were produced from nitrogen nuclei.
▪ Replaced the air with pure nitrogen gas.
▪ Resulted in the production of more nuclei.
▪ Hydrogen nuclei is part of all other atoms.
▪ Proton — positively charged particle with same
mass as hydrogen atom

25. ▪ To compensate for the mass of atoms of
elements, the nuclear electron hypothesis was
proposed.
▪ Example, the known charge of the nitrogen
nucleus was +7, but it has a mass equivalent to
14 protons
▪ The assumption does not agree with
observations.
▪ An electron could not exist in the nucleus.

26. • The concept of a neutral
particle inside the nucleus
was first hypothesized by
Rutherford.
• James Chadwick
• Explained the nature of an
uncharged radiation
produced by an
experiment