Matter, Energy & Environment

Interrelated Scientific Principles: Matter, Energy & Environment

• Lesson 2 explores the interconnected scientific principles involving matter, energy, and the environment.

Composition of the Lesson

• The lesson encompasses the nature of science, the structure of matter, energy principles, and the environmental implications of energy flow.

Nature of Science

• Assumptions of science, cause and effect relationships, and the scientific method are covered.

Assumptions of Science

• Specific causes underlie observed events in the natural world.
• These causes can be identified.
• General rules or patterns describe what happens in nature.
• Events that occur repeatedly likely have the same cause each time.
• What one person perceives can be perceived by others.
• The fundamental rules of nature apply regardless of location or time.

Cause-Effect Relationship

• This exists when an event is a direct result of a previous event.
• Enables predictions about future events under similar circumstances.
• Human activities can lead to global warming, which can cause climate change and natural calamities.

Scientific Method

• It involves a systematic process for acquiring scientific knowledge to solve problems.
• Steps include:
  • Making an observation/inquiry.
  • Researching the problem.
  • Formulating a hypothesis.
  • Conducting experiments.
  • Analyzing the gathered data.
  • Drawing a conclusion.
  • Sharing the results of the study.

Structure of Matter

• The study encompasses atomic and molecular structure, classification of matter, acids versus bases, and states of matter.

Atomic & Molecular Structure of Matter

• An atom is the basic unit of all matter in the universe.
• Atoms are fundamental blocks that combine to form matter and retain the element's properties.
• Molecules consist of two or more atoms combined using various bonds to form compounds, such as H2O (water) and CO2 (carbon dioxide).

Subatomic Particles

• Protons are positively charged particles found in the nucleus of an atom.
• Electrons are negatively charged particles in energy shells surrounding the nucleus.
• Neutrons are neutral particles in the nucleus, along with protons.

Classification of Matter

• Matter can be classified into:
  • Pure substances.
  • Mixtures.

Pure Substance

• Pure substances consist of only one type of particle.
• Elements are pure substances containing only one type of atom, which cannot be broken down further.
• Compounds are substances made of more than one atom and can be separated by chemicals.

Mixtures

• Mixtures are combinations of two or more substances where each retains its chemical identity and properties.
• Homogeneous mixtures have a uniform composition throughout, like salt in water or air.
• Heterogeneous mixtures have a non-uniform composition, with visually distinguishable components. Example; pizza or burger.

Acids vs. Bases & the pH Scale

• pH scale measures acidity and basicity, determining the strength of acids and bases.
• It's a universal indicator showing different colors at different concentrations of hydrogen ions.
• The term pH means potential of Hydrogen or simple power of hydrogen.
• It helps determine the nature of a solution based on hydrogen ion concentration.

pH of Acids

• Acids donate a proton.
• Acids can form a covalent bond with an electron pair.
• Acids generally taste sour and are corrosive.
• Acids turn blue litmus paper red.
• The pH value for acids ranges from 0-6.9.
• Lower pH values indicate stronger acids; pH 0-4 are strong acids.

Examples of Acids

• Battery acid has a pH value of 0.
• Hydrochloric acid has a pH value of 1.
• Lemon juice and vinegar have a pH value of 2.
• Orange juice and soda have a pH value of 3.
• Acid rain and tomato have a pH value of 4.
• Bananas and coffee have a pH value of 5.
• Milk has a pH value of 6.

pH of Bases

• Bases accept a proton .
• Bases acids consist of OH- ions.
• Bases generally taste bitter and are termed alkaline.
• Bases turn red litmus paper blue.
• The pH for bases ranges from 7.1-14.
• Higher pH values indicate stronger bases; pH 7.1-11 are weak bases.

Examples of Bases

• Seawater has a pH value of 8.
• Baking soda has a pH value of 9.
• Antacid tablets have a pH value of 10.
• Soap has a pH value of 11.
• Ammonia has a pH value of 12.
• Bleach has a pH value of 13.
• Drain cleaner has a pH value of 14.

States of Matter

• Matter has mass and occupies space.
• Space occupied by a substance is known as 'volume'.
• Mass is the quantity of metal in an object.
• Matter consists of atoms made of electrons, protons, and neutrons.
• Matter has various states and can be converted between them by adding or removing energy.

Solid State

• Solids have a definite shape and volume, like an ice cube or wood.
• Particles are tightly packed with minimal intermolecular space.

Liquid State

• Liquids have a definite volume but no definite shape, like water and milk.
• Particles are free to move with comparatively high intermolecular spaces.
• Liquids easily change their shape.

Gas State

• Gases have neither definite shape nor volume, like nitrogen and oxygen.
• Particles are far apart and move freely.
• Gases are highly compressible.

Plasma State

• Plasma is the fourth state of matter, a mix of free electrons and ions found naturally in stars.
• Plasma consists of particles with high kinetic energy and can be made by passing high voltage electricity through noble gases.

Bose-Einstein Condensates

• Bose-Einstein Condensates were discovered in 1995.
• Achieved by supercooling Rubidium to near absolute zero, causing particle motion and kinetic energy to become negligible.
• This state has no practical application but is used for research and behaves as a superfluid.

Change of State of Matter

• Matter can change states through sublimation, melting, evaporation, freezing, condensation, and deposition, due to heat energy taken from or released into the environment.

Energy Principles

• Chemical reactions, photosynthesis and cell respiration, types of energy, and the laws of thermodynamics are discussed.

Chemical Reactions

• Energy is conserved in chemical reactions; the total energy remains the same before and after reactions.
• Reactions are classified as exorthermic and endothermic.

Endothermic Reactions

• These reactions absorb heat energy from their environment.
• Examples include liquids evaporating, ice melting, and thermal breakdown.
• "Endo" and "thermic" imply "to absorb" and "heat."
• Enthalpy, or change in heat energy, increases as reactants transform into products.

Exothermic Reactions

• Exothermic reactions release energy into the environment as heat or light, like neutralization, burning, and fuel reactions.
• "Exo" and "thermic" allude to "release" and "heat."
• Reactions release energy due to a higher level of bond creation in products.
• Enthalpy change decreases, releasing a significant amount of energy during reactions between molecules and compounds and during bond breakage.

Difference between Endothermic and Exothermic Reactions

• Exothermic reactions release heat energy from a system while endothermic ones absorb energy from surroundings.
• Exothermic systems release energy while endothermic absorb it.
• Examples of exothermic reactions are rust, settling, chemical bods, explosions etc.
• Examples of endothermic reactions are ice melting, evaporation, cooking, molecules and photosynthesis.

Photosynthesis & Cell Respiration

• The two reactions involve a complex and natural process between sunlight, carbon dioxide and water into glucose (chemical energy) and oxygen

Photosynthesis

• Involves the use of sunlight and carbon dioxide.
• Water produces glucose and oxygen, releasing oxygen into the atmosphere.
• Glucose is used as chemical energy.
• Chloroplasts:
  • Consists of chlorophyll.
  • Is typically found in plant leaves.
  • Its pigments absorb light energy.
  • Converts the energy in light for transforming food.

Cellular Respiration

• The process occurs in living things.
• Cells turn nutrients into adenosine triphosphate (ATP).
• ATP acts as the source of energy.
• Glycolysis and the Krebs cycle are the first of the 3 steps, followed by the transport system.

Types of Energy

• Energy is the capacity to do work or bring a change.
• Energy transforms from one type to another.
• Types of Energy: The are different forms, heat, light and sound.
• Kinetic and Potential Energy are the main two.
• Kinetic Energy is the energy associated with an object's movement.
• Potential Energy is the energy stored by an object due to its state, arrangement or position.

Forms of Energy

• Forms can be categorized as:
  • Kinetic.
  • Potential.

Potential Energy

• Radiant energy travels as waves or particles, commonly experienced as heat.
• Thermal energy occurs when temperature increase atoms to move faster.
• Sound energy travels through a medium and is translated into electrical signals by the human brain.
• Electrical energy relates to the move of electric particles.
• Mechanical energy is that form of kinetic energy related to objects, it includes potential energy.

Potential Energy

• Chemical energy is stored in food and fuel.
• Elastic energy is stored in stretched objects.
• Nuclear energy is stored in the center of particles.
• Gravitational energy is stored in an object relative to Earth's surface.

Laws of Thermodynamics

• First Law: Energy cannot be created or destroyed.
• First Law: It can only be converted to a form of energy.
• Some heat changes the internal energy, the rest is used to perform work
• This is known as the law of conversation of energy.
• Second Law: Energy converted from one form to another loses some useful energy.
• Entropy is the useless energy that cannot perform effective work.
• The universe's entropy increases.

Environmental Implications of Energy Flow

• Entropy Increases: Orderly arrangements turn disordered, like living things dieing.
• Energy Quality: Some forms of energy are more useful, like Electrical vs Ocean's Heat Energy.
• Biological Systems: All organisms convert to low quantity, like Photosynthesis & Respiration.
• Pollution: Heat from energy conversions creates pollution.
• Less energy consumption means less waster, making less pollution.