Matter and Energy #1
1. States/ Properties/Changes
2. Forms & Transfer of Energy
Matter
Section 1
• Anything that HAS MASS and
they OCCUPY SPACE.
• Ex? – List 5.
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).
http://titanium.fullerton.edu/shock/PHASED.htm
Plasma
MOST
AMOUNT OF
ENERGY
• Usually an ionized
gas.
• Does not definite
shape.
• Conducts electricity
well.
• Effected by electric
and magnetic fields.
• http://www.harcourtschool.com/
activity/states_of_matter/
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.
Changes in State cont.
• Energy Released- during
condensation. Gas → Liquid or
Liquid → solid.
• Changes of state:
•
solid → liquid → gas, does not change
the composition or the mass.
Laws of Conservation
• Law of Conservation of Matter:
Matter cannot be created or
destroyed.
• Law of Conservation of Energy:
Energy cannot be created or
destroyed. (This is the 1st law
of thermodynamics!)
Properties of Matter
•
Chemical Properties: how a substance
reacts with other substances,
chemically, to form new *** composition
will be changed***substances.
•
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.
•
Ex: rust (the ability of iron to react with oxygen),
and combustion/flammability. Electronegativity,
ionization potential, pH , heat of combustion,
toxicity, stability, flammability…
Properties of Matter
cont.
•
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
Prop. Of Matter cont.
•
•
•
•
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**
Prop. Of Matter cont.
• Melting, freezing and evaporation are
physical changes. So is dissolving…
• Ex: sugar water. The Sugar
molecules are not changed… they
only spread out in the water. Proof?
The water still tastes sweet; thus,
dissolving is a physical change.
Energy (heat) Transfer
A Review
• Radiation- energy transfer
through empty space.
• No direct contact is required to transfer
heat.
• Conduction- heat transfer by
DIRECT CONTACT
• Convection- Heat transfer by
the movement of a heated fluid.
Energy (heat) Transfer
A Review
• Energy (heat) always transfers
from HIGH to LOW.
from low to high.
NEVER
Conductors vs. Insulators
• Conductor- matter which allow
current/heat to flow.
• Currents flow via ELECTRONS
jumping from one atom to the
next.
http://www.ndted.org/EducationResources/HighSchool/Electricity/conductorsinsulator
s.htm
Conductor
Insulator
• Insulator- matter which resists
the flow of current/ heat.
CALCULATING DENSITY
• Which box would weigh more? Why?
•
The box that has more red balls (more mass per unit of volume).
• This property of matter is called density.
• Density is expressed in g/cm3.
CALCULATING DENSITY
• The formula for calculating density is:
• Solve: A piece of tin has a mass of 16.25g and a
volume of 2.26 cm3. What is the density of the tin?
• A man has a 50.0 cm3 bottle completely filled with
163g of a slimy green liquid. What is the density of
the liquid?
• A piece of metal has a density of 11.3 g/cm3 and a
volume of 6.7cm3. What is the mass of the metal?