CHAPTER 2 THE CHEMICAL CONTEXT OF LIFE
MATTER AND ITS DIFFERENT STATES
Matter is anything that has mass and takes up space
o Anything that you can and cannot see
o Everything that is not empty space
States of matter
o 3 main forms on earth for biological organisms
o Can depend on pressure, temp, and if its interaction with other forms
o Liquid: No regular arrangement of particles that takes up the shape of its
container. The particles stick closely together and can be penetrated
o Solid: Regularly arranged particles that help make up a specific shape or
arrangement. Its particles are close together where it can’t be penetrated
o Gas: Tend to take on the shape of its container that they’re placed in. Its particles
are placed far apart which makes it easier to penetrate
Matter consists of chemical elements in pure forms and also in compounds which are a
combination of elements
THE PROCESSES MATTER CAN USE TO CHANGE ITS STATE
Evaporation: Liquid to gas
o EX: Gas
Condensation: Gas to a liquid
o EX: water droplets on a car
Melting: Solid to a liquid
o EX: Melting ice
Freezing: Liquid to a solid
o EX: Freeze water
Sublimation: Solid to a Gas
o EX: Ice in a freezer that is placed in for too long
Deposition: Gas to a Solid
ELEMENTS VS COMPOUNDS
Compounds: A substance that consistent of two or more different elements that are
combined in a fixed ratio.
o Distinguishing Features: contains different elements in definite quantities and
proportions by chemical bonds
o Ability to breakdown: Can be separated into simpler substances by chemical
methods
o Type #: endless amounts of compounds
o Properties: Depend on its atoms and how they are bonded together
When elements combine, individual properties of the atom are lost and
new properties are created from the elements it is composed of
o Represented: by Formula
o Examples: Sodium (Na) + Chlorine (Cl) = Sodium Chloride (NaCl) 1:1 ratio
Elements: A pure substance that cannot be broken down to other substances by chemical
or physical means. Simplest Form.
, o Distinguishing Features: Each element has their own atomic structure and
chemical properties as a result of their unique arrangement of subatomic particles.
They can be distinguished by their atomical number.
o Classified: Classified by their properties
Boiling Point
Melting Point
Density
Reactivity
o Ability to breakdown: Cannot be broken down into a simpler substance by
chemical reactions
o Type #: 92 naturally occurring elements with 117 total is being observed
o Represented: Using atomic symbols
o Examples: Iron (Fe) or Copper (Cu)
ESSENTIAL ELEMENTS
Elements needed by an organism to live a healthy life
o Humans = 25 Elements needed to live
o Plants = 17 elements needed to live
Out of 92 naturally occurring elements, only 20-25% are essential for organisms to use
and reproduce
Same amongst all different organisms but they do have different variations since some
can be toxic for different organisms
Elements that make up 96% that are essential for living matter
o Oxygen (O)
o Carbon (C)
o Hydrogen (H)
o Nitrogen (N)
Elements that make up 4% essential for an organism’s mass
o Calcium (Ca)
o Phosphorous (P)
o Potassium (K)
o Sulfur (S)
TRACE ELEMENTS
Required by organisms in only small amounts and only in minute quantities
o Can be needed by all forms of life while certain species only require some
o Nitrogen Deficiency
o Iodine deficiency
Have a mass of at least 0.01%
Required in amounts less than 100 per day
Elements
o Iron (Fe): A trace element that is required by all organism
o Arsenic (As): Naturally occurring element that is toxic to most organism
Trace elements that are required for only some
o Vertebrates for gland activity = Iodine (I)
Primary Function
o Catalyze in enzyme systems
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