Chemistry and You
Paclitaxel
Natural Science

3 Branches
•
Biological Sciences- the science of living things
•
Physical Science- the science of matter & energy
•
Earth Science (Geology)- the science of Earth
• Botany, Zoology, Ecology, etc.
• Physics- forces and energy
• Chemistry
• Geology, Meteorology, etc.
What is Chemistry?

Chemistry- The study of all
substances (matter) and the
changes that they can undergo.
• Medicine, fibers, dyes, food,
perfume, developing film, wine
making, production of Gas (oil),
cleaning products, etc.
• Can you think of some examples of
when a chemistry is happening?
The Central Science

Chemistry is considered the central science
because it overlaps so many other
sciences.
• Biology, Medicine, Physics, Astronomy, Geology,
etc.

And jobs!
• Engineering, public service, hair dresser, dental
assistant, Nurse, Candy maker, Steel worker,
Firefighter, Forensic Scientist, Medical examiner,
etc.
Matter

Matter is anything that HAS MASS and
TAKES UP SPACE.

4 States- solid, liquid, gas and plasma
Composition of Matter

Matter is comprised of:
• Atoms- the smallest unit of an element
• Elements- a substance that cannot be broken
down into a smaller substance
• Elements are represented by a 1 or 2 letter symbol.
• EX: C is carbon, O is oxygen, Fe is iron, Al is aluminum
and Na is sodium.
• There are more than 110 elements we know of and all
have distinct properties and behaviors.
• Compounds- a substance made of 2 or more
elements.
• When 2 or more elements combine chemically they form
a compound. Every compound is unique and different
from the elements it contains.
• Compounds have set ratios.
• EX: Sugar C6H12O6.
• EX: Water (H2O) will always have 2 H atoms to every 1 O
atom.


Molecules: when elements combine to
form compounds, the smallest unit that
exhibits all the properties of the
compound is a molecule.
Most molecules are made of atoms from
different elements (H2O) but some are
made of the same element.
•
EX: Ne, O2, H2, Cl2, P4, S8.
• EX of compounds
Chemical Formulas

Chemical Formula: shows how many of each
element are a molecule (the basic unit) of a
compound.
•

The # is written as a subscript. NO subscript is used
to denote ONE. EX: Carbon dioxide is CO2 not C1O2.
When a # is placed in front of a chemical
formula, it represents how many molecules
present.
•
EX: 9 C6H12O6 means that you have 9 sugar
molecules.
REVIEW SECTION

Kinetic Theory
• Describes the behavior of matter
• All matter is made of atoms and molecules that act like tiny
particles.
• These tiny particles are always in motion. The higher the
temperature, the faster the particles move.
• At the same temperature, the massive (heavier) particles
move slower than the less massive (lighter) particles.
4 States of Matter

There are 4 states of matter the kinetic
theory helps describe: solids, liquids,
gases and plasma.
• These states of matter are physically different.
Solid


LEAST
AMOUNT
OF
ENERGY
Molecules do not move freely,
they vibrate in place, giving
solids a rigid structure.
They have ordered, fixed, and
tightly packed arrangements
due to chemical bonding and
intramolecular interactions
Liquids



Molecules are closer together and moves
faster than solids.
Molecules are weakly attracted to one
another moving less freely than gas. They
move randomly and fill the container in
which they are held.
The rate at which a liquid moves/flows is
known as its viscosity. The slower
moving= more viscous. Ex: Glass.
Gases




molecules are in constant, random
motion spreading out in all directions
(diffusion).
They exert pressure. The pressure is
made by individual gas molecules hitting
the sides of the container.
As the temperature rises, the molecules
begin to move faster = the pressure
increases
(the molecules hit the sides more often
and with greater energy/force=
increased pressure).
Plasma




MOST
AMOUNT
OF
ENERGY
Usually an ionized
gas.
Does not definite
shape.
Conducts electricity
well.
Effected by electric
and magnetic fields.
Changes in State

Energy’s Role: required to move or change matter.
Energy is transferred in all changes of state.
•
•


ENERGY REQUIRED- to melt or evaporate any substance.
Sublimation- physical change of a solid to gas- energy is
required.
Energy Released- during condensation. Gas →
Liquid or Liquid → solid.
Changes of state:
•
solid → liquid → gas, does not change the composition or the
mass.
Law of Conservation of Matter/Mass

Law of Conservation of Matter/Mass:
Matter/mass cannot be created or
destroyed.
• It only changes form.
Properties of Matter

Chemical Properties: how a substance reacts with
other substances, chemically, to form new
substances. *** composition will be changed***
•

Ex: rust (the ability of iron to react with oxygen), and
combustion/flammability. Electronegativity, ionization potential, pH ,
heat of combustion, toxicity, stability, flammability…
Reactivity- the ability of a substance to react
chemically with another substance. How much it will
react depends on what they are reacting with and in
what kind of environment the rxn is occurring.

Physical Properties: characteristics of the
substance which can be measured/observed
without changing the composition of the substance.
•
•
•
•
Melting point- temp. @ which a solid becomes a liquid.
Boiling point- temp. @ which a liquid becomes a gas.
Density- the mass per unit volume.
Buoyancy- the force with which a more dense fluid pushes
a less dense substance upward.
• * These properties help determine the use of the compound. *
Prop. Of Matter cont.

Chemical Changes: occurs
when a substance changes
composition to form a new
substance.
• Na2O + H2O→ 2NaOH

Combustion:
CH4 + 2O2→ CO2 + 2H2O

Physical Changes: only the physical
properties/form change. The substance may look
different but the atoms of the substance are not
changed.
• Ex: changes of state- solid to liquid to gas. The substance looks different
but the composition remains the same (H2O is still H2O).
• Grinding peanuts to make peanut butter.
• Pounding a gold nugget to make a ring
•
** The melting point, density or color of gold doesn’t change**
• Melting, freezing & evaporation = physical changes.
• So is dissolving…