Lecture 2 Flashcards
How many naturally occurring elements are there
92
Compounds and elements are ________ Substances
Pure
True or false; Pure substances can be separated into smaller parts by physical means
False, cannot
True or false; Solutions and mixtures are able to be separated into smaller parts?
True
True or false; Elements can be separated by chemical reactions
False
True or false; Atoms are the largest unit of chemical matter
False, smaller
An allotrope is
An element that has more than on stable form ,
ex; oxygen, o2 and o3
Protons are located where
in the nucleus
Electrons are located where
they orbit a molecule
Neutrons are located where
The nucleus
Neutrons weigh the sane as _____ but have ___ charge
Protons, no charge
Isotopes are
when an element can have different numbers of neutrons
ex; Hydrogen, 1H, 2H, 3H
What makes the atomic weight of an element
the number of protons plus neutrons
Unpolluted dry air at sea level and standard pressure contains what three major constitutes and what 5 minor gases
major: Nitrogen, oxygen, argone
Minor: Carbon dioxide, Ne, Helium, CH4, N2O3
Most environmental issues result from change in the __________ gases
minor
99% of the Earths atmosphere is below _____ and has a mass of ______
30km
5 X 10^15 Tonnes
What are the layers of the Atmosphere?
Troposphere
Stratosphere
Mesosphere
The Troposphere is located where
0-10 km from the earths surface ( Most life lives here )
The straotosphere is located where
10-50 km
The mesosphere is located where
50+ km from the earths surface
What are the main environmental issue with the Troposphere?
Climate Change
What are the main environmental issue with the Stratosphere
Hole in the Ozone layer
What is a Biogeochemical cycle?
The constant movement of gases in and out of the atmosphere
What are the sinks and sources of the biogeochemical cycles
Sinks: Where a gas goes too
Sources: are where a gas originates
Gases move at ____ rates
Different
