Upload
locke
View
78
Download
0
Embed Size (px)
DESCRIPTION
Ch. 3: “Atoms & the Periodic Table”. Section 3.1 Review: “Atomic Structure”. 1. Summarize the main ideas of Dalton’s atomic theory. Elements are made of tiny, unique particles called atoms. Atoms cannot be divided. Atoms of the same element are identical. - PowerPoint PPT Presentation
Citation preview
Ch. 3: “Atoms & the Periodic Table”
Section 3.1 Review: “Atomic Structure”
1. Summarize the main ideas of Dalton’s atomic theory. Elements are made of tiny, unique
particles called atoms. Atoms cannot be divided. Atoms of the same element are identical. Atoms of different elements can join to
form molecules.
2. Explain why Dalton’s theory was more successful than Democritus’s theory.
Evidence existed to support Dalton’s theory.
3. List the charge, mass, & location of each of the 3 subatomic particles found within atoms. proton: +1, 1.67 x 10-27kg, in the nucleus neutron: 0, 1.67 x 10-27kg, in the nucleus electron: -1, 9.11 x 10-31kg, outside the
nucleus
4. Predict how many valence e-’s a nitrogen atom has. (Nitrogen has a total of 7 e-’s, 2 of which fill the lowest energy level.)
5 valence e-’s
5. Explain why oxygen atoms are neutral. (Oxygen has 8 positively charged p+’s.)
Oxygen has 8 negatively charged e-’s to balance out the charge of the 8 positively charged p+’s.
6. Compare an atom’s structure to a ladder. What parts of the ladder correspond to the energy levels of the atom? Identify one way a real ladder is not a good model for the atom.
The nucleus is underground. Each rung of the ladder represents an energy level. Electrons can only be on the rungs, not between rungs.
A ladder is not a good model for an atom because all of the rungs are the same distance apart.
7. Explain how the path of an e- differs in Bohr’s model & in the modern model of the atom.
In Bohr’s model, e-’s travel in fixed paths. In the modern model, e-’s exist in certain
regions & can have only certain energies.
8. Critical Thinking
What do you think the majority of an atom is made of?
empty space
What part of the atom caused the particles to bounce back?
the nucleus