Transcript Basic Chemistry - eastmarinedrive

Basic Chemistry
What is Matter?
• Matter is anything that has mass and
takes up space.
• Matter can be found in 4 distinct phases:
solid, liquid, gas, and plasma.
• Matter is composed of small units called
atoms.
What is an Atom?
• An atom is the basic
unit of matter.
• It is composed of
negatively charge
electrons spinning
around a nucleus
containing positively
charged protons and
non charged
neutrons.
Atomic Number and Atomic
Mass
• The atomic number of an atom is the
number of protons it contains in its
nucleus.
• Sometime it may also equal the number of
its electrons.
• The atomic mass of an atom is the total
number of its protons and neutrons.
Chemical Elements
• Atoms have been grouped according to their
atomic number and mass into units called
elements.
• There are 109 of these elements known to man,
which 90 of them occur naturally.
• These elements are represented by symbols.
• The Periodic Table contains the complete list of
these elements.
Periodic Table
Chemical Compounds
• Are formed when 2 or
more different
elements combine.
• The upper example is
a molecule of glucose
while the lower one is
2 water molecules.
What Holds Chemical Compounds
Together?
• Atoms need to be stable.
• In order for this to occur they must completely fill
their outer level of electrons.
• This usually requires 8.
• Most atoms are lacking anywhere from 1 to 7
electrons.
• Hydrogen is lacking 7, while Chlorine is lacking
1.
Types of Chemical Bonds
• Ionic
• Covalent
Ionic Bond
• This type of bond is formed when one element
takes the electron it needs from another
element.
• This causes one element to become a + ion
due to the loss of its electron and the other a
negative - ion due to the gain of the electron.
• The bond is formed by the attraction of the +
element to the - element.
• Example: 2Na+ ------> Cl2- = 2NaCl
Covalent Bond
• This type of bond is formed by the
sharing of electrons between different
atoms.
• It is a strong bond.
• Examples: 2H2 + O2 ----> 2H2O
Structural Formula
• What is the C in the
compound Alanine?
• What is the line
represent between
the C and C?
• What does the 2 and
3 represent?
Chemical Reactions.
• 2H2 + O2 ----> 2H2O
• Chemical reactions like the one above
contain two parts: The reactants and the
products.
• The reactants are on the left of the arrow,
while the products are to the right.
What is pH?
• pH is the negative log of the Hydrogen
ions concentration in solution.
• Water’s chemical formula is H2O. Or
• H-O-H.
• Water has the ability to split into 2
separate ions: H+ and OH-.
• If these ions are in balance than the
solution’s pH is neutral or 7.
pH Scale
• The pH scale is based on the number 10.
• 7 is the middle or neutral.
• Acids contain more H+ in solution than the OHions. Any number below 7 is considered acidic.
• Bases contain more OH- ions than H+ ions. Any
number higher than 7 is considered a base.
• pH is a very important variable in all chemical
reactions.
pH Scale
Problems
• If stomach acid has a pH of 1, and a
person took a tums tablet which raised the
pH to 3, how much was the increase in
pH?
• What is acid rain?
• How would we make an acidic lake normal
again?