Chapter 2 - Protecting the Ozone Layer Flashcards
What is the formula for ozone?
energy + 3 O2 –> 2 O3
What is ozone?
an allotropic form of energy (different form of same element, differ in structure and properties)
What are the characteristics of oxygen?
- colorless gas
- odorless
- light blue liquid
- boiling point: -193 degrees (gas –> liquid)
- reactive (supports combustion)
What are the characteristics of ozone?
- colorless gas
- definite odor
- dark blue liquid
- boiling point: -112 degrees (gas –> liquid)
- very reactive
Where is ozone found?
- majority in stratosphere
- also found in troposphere (ozone increases from pollution)
Good vs. Bad Ozone
Good: in upper atmosphere ozone blocks UV rays
-90% of ozone is in “ozone layer” (9.3-18.6 miles above ground)
Bad: lower atmosphere ozone produces photochemical smog
-10% of ozone here at 1.5 miles above ground and lower
What is the structure of an atom?
nucleus: center, dense, contains protons/neutrons
electrons: orbit nucleus
What are the elementary particles of atoms?
- Electrons
- negative charge
- orbit atom nucleus
- very tiny (compared to protons/neutrons) - Protons
- positive charge
- in nucleus
- 2000x size of electron - Neutrons
- no charge
- in nucleus
- 2000x electron size (but heavier than protons)
What are the protons and neutrons called?
nuclons
What is a neutral atom?
when the # of protons = # of electrons
What determines an element’s identity?
depends on # of protons (atomic #, above symbol)
What are ions?
when an element has a different number of electrons
-atomic particle with a charge
–>ex. 17 protons and 18 electrons = +1 charge
17 protons and 16 electrons = -1 charge
What are isotopes?
when an element has a different number of neutrons
–>ex. 6p, 6n, 6e = Carbon-12
6p, 7n, 6e = Carbon-13
6p, 8n, 6e = Carbon-14
What are neutrons?
- uncharged
- add mass to atoms
- change # of neutrons –> same kind of atom physically, reacts the same, same mass, may affect stability (heavier = less stability –> isotopes
26
F
Iron
55.85
atomic number
atomic symbol
atomic name
atomic mass (not mass #)
What does changing the number of particles do?
- protons –> identity of atom
- neutrons –> isotopes
- electrons –> ions
What are valence electrons?
larger atoms - many electron layers
- shells/layers
- valence = outermost electrons
- involved in reactions
- determine chemical properties
- “want” same # of valence electrons as nearest Group 8A element (noble gases-stable/unreactive)
- Group # tells number of valence electrons
What are molecules?
when 2 or more atoms are bound
What is a covalent bond?
when atoms share electrons
- 2 electrons shared between 2 atoms = single covalent bond
- 4 electrons shared between 2 atoms = double covalent bond
- 6 electrons shared between 2 atoms = triple covalent bond
What are Lewis Structures?
Show the electron pairing between atoms