Download - Basics of Chemistry
Basics of Chemistry
Week 4
Dr. Thornton
OAPB
electronshell
nucleus
Hydrogen (H) Helium (He)
neutron(no charge)
proton(positive charge)
electron (negative charge)
The Atom by Niels Bohr
The Bohr Model
Electron Shells
Elements
• Matter: takes up space, has weight.
• Mass: the quantity of matter in a given object.
• Energy: review the types of energy.
Isotopes
electrontransfer
sodium ion (Na+) chloride ion (CI–)
ATOM ACTIVITY!
Polar Molecules
ice
In ice, the maximum numberof hydrogen bonds form,causing the molecules to bespread far apart.
liquidwater
In liquid water, hydrogenbonds constantly break andre-form, enabling a moredense spacing than in ice.
pure water
(H2O)
(a) Starting with pure water
Pure water is a “neutral”substance in terms of itspH levels.
(c) Making watermore basic
An equal concentration of sodium hydroxide, poured into water, dissociates into Na+ and OH– ions, moving the water toward the basic end of the scale.
base
NaOH
neutralized solution
(d) Combining acidic and basic solutions
When the acid and base solutions are poured together, the OH– ions from (c) accept the H+ ions from (b), formingwater and keeping the solution at a neutral pH.