Name: ______________________
Biology 135
Ch. 2, Sections 1 & 2
The Nature of Matter
Chapter 2, Section 1
(Pages 35-41)
Elements
Definition:
________________________________________________________________________
________________________________________________________________________
About two dozens found in living things
Isotopes
Definition______________________________________________________________
________________________________________________________________________
Identified by their ___________ _____________
Example: Carbon-12, Carbon-13, Carbon-14
Chemical Bonds
Atoms in compounds are held together by chemical bonds
Bonds involve the _____________ that surround the ______________
Ionic Bond
Definition:
________________________________________________________________________
________________________________________________________________________
Atoms are normally ______________
If an atom loses an electron, it has a _____________ charge
If an atom gains an electron, it has a _____________ charge
Charged atoms are known as ____________
Covalent Bonds
Definition:
________________________________________________________________________
________________________________________________________________________
Moving electrons actually travel in the orbitals of both atoms
If they share two electrons: _________________ covalent bond
If they share four electrons: _________________ covalent bond
Molecule:
________________________________________________________________________
Formed when atoms are combined by __________________ bonds
Properties of Water
Chapter 2, Section 2
(Pages 40-43)
Name: ______________________
Biology 135
Ch. 2, Sections 1 & 2
Chemical Compounds
Definition:
________________________________________________________________________
________________________________________________________________________
Shown by a chemical _______________________
Ex: H2O, NaCl
The properties of a compound are usually very different than the individual elements
that make them up
& Oxygen by themselves can be very explosive – together they give us
___________
Sodium is a silver-colored _____________ that is soft enough to cut with a knife,
explodes when mixed with cold water; Chlorine is a poisonous greenish __________
used to kill in WWI – together they give us table ____________
Hydrogen
The Water Molecule
Polarity
The ______ protons of Oxygen has a stronger attraction for electrons than the Hydrogen
atoms with ______ proton
Gives the water molecule a __________ shape
Oxygen end has a slight _____________ charge
Hydrogen end has a slight ____________ charge
Because of
their partial positive and negative charges, polar molecules can
______________ each other
Attraction between the hydrogen atom of one water molecule and the oxygen atom of
another water molecule creates a _____________ bond
Cohesion
_____________________________________________________________________
Because
of hydrogen bonding, water is extremely ______________
of water form beads on a smooth surface
Why insects and spiders can walk on a pond’s surface
Why drops
Adhesion
______________________________________________________________________
Ex:
the surface of water in a graduated cylinder dips slightly in the center because the
adhesion between water molecules and glass molecules is stronger than the cohesion
between water molecules