Energy & Matter. 2.1, 1.1, 1.2, 1.3. 1. Energy (2.1). Energy : The capacity to do work or produce heat . 7 types of energy: • mechanical • thermal (heat) • radiant (light) • sound • electrical • chemical • nuclear. 2. Kinetic Energy : Energy of motion.
2.1, 1.1, 1.2, 1.3
• thermal (heat)
• radiant (light)
4. Energy can be transferred from a system to its surroundings.
Ex. Photosynthesis is light → chemical
5. Energy absorbing changes are called endothermic. If energy is released the change is called exothermic.
1. Common Unit: calorie The amount of heatneeded to raise 1g of water 1oC. (One calorie = 1g°C)
2. SI Unit for energy: Joule (J)
C. Law of Conservation of Energy:
Energy is neither created nor destroyed, it just changes form.
1. Energy can be transferred in the form of
2. Temperature is a measurement of heat or
kinetic energy. (how fast the average
particle is moving!)
Heat vs. Temperature Animation
Kinetic Energy (Temperature) and Melting
Room Temp 20°C→
Room Temp 70°F→
← Room Temp 293 K
K = °C + 273
°C = K - 273
4. Kelvin: °C = K
5. The zero point on the Kelvin scale is called absolute zero (-273°C)
6. All motion of particles stops! Therefore the kinetic energy is zero.
1. Volume: Amount of space an object takes up.
2. Mass: Quantity of matter in a substance. Constant everywhere. Ex) the moon
3. Weight: Force produced by gravity acting on a mass. This is different in different locations.
Mass does not depend on gravity. The mass of an object remains the same in all locations.
Weight depends on gravity. Weight equals Mass x gravity. The weight of an object changes with location.
Weight and Mass Demo
1. Physical: density, color, melting point, viscosity, surface tension, specific heat
2. Chemical: flammability, reactivity with other
chemicals or air (O2)
C. States of Matter (1.1):
Plasma is the 4th state of matter “ionized gas” like the sun/fluorscent lights
1. Gasespossess the greatest amount of kinetic energy.
2. Two factors that determine the state of matter of a substance: speed of the particlesand the distance between them.
3. These two factors contribute to the attractionbetween the particles.
4. Substances changephasewhen they overcome these attractions.
5. The overallkineticenergy(temperature) will remain constant until the entire substance has completely changed phase.
1. Physical Changes:
changes of state
evaporation –at the surface
boiling - throughout
Gases are in the gaseous state at room temp.
Vapors are in the solid or liquid state at room temp.
Comparison of the three states of matter
Density = .998 g/mL
Ice Density = .92g/mL
a. Alter the identityof the substance.
b. The new substance has different properties
than the original substance.
c. Examples of Chemical Changes: burning, rusting
d. Signs that a chemical change has occurred:
1. gas released (bubbles/odor/fizz/smoke)
2. color change (can be physical too)
3. formation of a precipitate (insoluble solid that
falls out of solution.)
4. temperature change (can be physical also)
G. Classification of Matter (1.3)
1. Pure substances: Substances that have a uniqueset of
physical and chemicalproperties.
a. Elements: The smallest part of an element is
1. Cannot be separated into simpler substances.
2. Represented by symbolsthat have 1or2letters.
Ex) K, Na, Au, Ag, Hg, Fe
(three lettered symbols are temporary)
Element Symbol: 1 or 2 letters (1st is a capital)
1. Made up of 2or more kinds of atoms
chemicallycombined in a fixed proportion.
2. Represented by formulas.
3. Examples: CO, CO2, H2O, NH3
Atomic Number: # of protons
Atomic Mass: (weighted average of all an elements’s isotopes)
a. Heterogeneous Mixture: Visibly different
throughout. Will separate upon standing.
Ex) salad dressing (emulsion), chocolate
chip cookies, sand & water (suspension)
b. Homogeneous Mixture: The same
throughout. May be clear, will not separate.
Ex) Kool-aid (solution)
gold jewelry (alloy)
Brass is an alloy of copper and zinc.
Bronze is an alloy of copper and tin.
Steel is an alloy of carbon and iron.
ex) gold jewelry
ex) sand & water
1. Heterogeneous Mixtures can be separated by:
a. Filtration- Material remaining on the filter paper is called the residue. The filtrate goes through the filter paper. Ex) sand & water
a. Distillation- separates liquids (and 1 solid) by differences in boiling point. The remaining material is called theresidue. The material that goes through is called the distillate.
Ex) alcohol & H2O
b. Crystallization- Evaporate liquid and the solid will crystallize. Ex) salt and water
c. Chromatography – used to separate pigments and ink by differences in solubility(density) on a strip of paper.Ex) black ink - rainbow
a. Electrolysis – decomposes a compound into its elements. Ex) water into H2 and O2