Science, Matter, Energy and Systems Miller and Spoolman, Ch 2

Pre-Assessment Probes What do you remember from prior classes and your summer assignment? Read through and respond to the three scenarios dealing with matter and systems. Include your responses on the PowerPoint (no names) Find the slide with your answer choice as the heading Give your reasoning in the content space below

Seedlings in a Jar

A. The total mass of the original jar with seeds will be more than the total mass of the jar with the seedlings. The plants grow, generating more cells and therefore more mass. because the plants now exist and produce oxygen

B. The total mass of the original jar with seeds will be less than the total mass of the jar with the seedlings. as these seedlings develop and grow roots, their mass will increase as the mass of the moist-to-dry towel decreases.

C. There will be no change in the total mass of the jar with seedlings after 12 days. due to the conservation of energy you can't make something out of nothing, so the mass stays the same. law of conservation of mass, jar is a closed system The system is closed, so the mass should stay the same because nothing is entering or leaving the jar (Mass cannot be created or destroyed).

C. There will be no change in the total mass of the jar with seedlings after 12 days. The law of conservation of mass states that matter is neither created or destroyed in any chance or reaction. Because mass cannot be created or dsetroyed

Chicken Eggs

Group A: We think an egg will gain mass Group A: We think an egg will gain mass. An egg’s mass is more just before hatching than when the egg was laid. after the egg is laid, it continues to grow and develop, gaining in size and mass. because it is growing as the chick develops organs and body parts, its mass will increase.

Group B: We think an egg will lose mass Group B: We think an egg will lose mass. An egg’s mass is less just before hatching than when the egg was laid. the mass of the water/moisture in the fertilized egg will be lost

Group C: We think the mass of an egg stays the same as the chick develops inside. due to the conversation of energy and mass  the chicken takes nutrients from the egg the chick will eat the yolk of the egg and the nutrients will become a part of the chick, so there is no mass gained or lost. The egg is a closed system, mass cannot be created or destryed and nothing is entering or leaving the system.

Group C: We think the mass of an egg stays the same as the chick develops inside. The egg, incubator combo is a closed system, and within a closed system, mass cannot be created or destoyed no matter can be created or destroyed so the system has 500 grams at the beginning and end Since no mass can be created or destroyed, the mass will stay the same

Is It a System?

Things that are systems Systems: everything except density= mass over volume, a box of nails and a graph Everything but the box of nails Aquarium, earth, grasshopper, volcano, ocean, digestion, food web, hurricane, seed, bicycle, earth and moon, cell phone, electrical circuit, water cycle, human body.

What is a system? any set of parts working together to form a complex whole a group of components that work together to form one thing. If different componenets of the thing needed to work together to operate, then we determined that it was a system

What is science? Scientists collect data and develop theories, models, and laws about how nature works.

Science is a search for order in nature Science is about working to understand how the natural world works and use that knowledge to make predictions about what is likely to happen in the future Conducted in a systematic manner: the scientific method/process Key features include curiosity, skepticism, peer review, reproducibility, and openness to new ideas.

Scientists use reasoning, imagination, and creativity Inductive reasoning Use specific observations and measurements to come to a conclusion You see examples and apply to all “Bottom up”  specific to general Deductive reasoning Logic based You know of ideas and apply to specifics “Top down”  general to specific.

Scientific theories and laws are the most important results of science Science theory vs. public theory Theory vs. law Theory: explanation of observations Law: observations Paradigm shift.

The results of science can be tentative, reliable or unreliable Check your source! (Think Wikipedia, media news, etc.) Tentative  frontier science; new stuff Reliable  lots of widely accepted data Unreliable  has not been subjected to peer review, or unsupported by peer review.

Environmental science has some limitations Scientists can disprove things, but they cannot prove anything absolutely (use “prove” with caution…or better yet, not at all) Scientists are human The world is a big place Many variables and complex interactions The scientific process only applies to the natural world, not ethics or morality.

What Is Matter? Matter consists of elements and compounds which are in turn made up of atoms, ions, or molecules

Matter consists of elements and compounds Matter: stuff (aka anything that takes up space and has mass) Elements: fundamental substance, cannot be broken down into anything simpler (ex. H and O) Compounds: Combinations of two or more elements in fixed proportions (ex. H2O)

Atoms, ions, and molecules are the building blocks of matter Atom: a single “piece” of an element Protons, neutrons, electrons Nucleus: protons & neutrons

Atoms, ions, and molecules are the building blocks of matter

Atoms, ions, and molecules are the building blocks of matter Isotopes: elements with the same atomic number but different mass Aka different number of neutrons Ion: elements with the same atomic number, but with a charge aka different number of electrons Why ions??!!?!?!?! WHY!??!?!?!?!?!? Different ions are essential for plant growth (ex. Nitrates) pH balance is critical for living organisms in both water and soil.

Atoms, ions, and molecules are the building blocks of matter Molecule: Combination of two or more atoms of the same or different elements held together by chemical bonds Chemical formula: shows the number of each type of atom or ion in a compound.

Organic Compounds are the Chemicals of Life Organic compounds: compounds that contain at least two carbon atoms, and at least one hydrogen atom Ex. Carbohydrates, proteins, lipids, nucleic acids, etc. Inorganic compounds: everything else Ex. CO2, O2, H2O, salts, etc.

Matter Comes to Life through Genes, Chromosomes and Cells

Matter Occurs in Various Physical Forms Matter can be found in one of three physical states: solid, liquid, or gas Depends on the spacing and orderliness of the of the molecules.

How Can Matter Change? When matter undergoes a physical or chemical change, no atoms are created or destroyed (the law of conservation of matter)

Matter Undergoes Physical, Chemical and Nuclear Changes Physical change: a change in which the arrangement of atoms or ions does not change Ex. Ice melting into liquid water Chemical change (aka chemical reaction): A change in the arrangement of atoms or ions Ex. Burning a piece of paper.

Matter Undergoes Physical, Chemical and Nuclear Changes Nuclear changes: change occurs in the nucleus of an atom Natural radioactive decay: isotopes spontaneously emit sub-atomic particles Nuclear fission: splitting apart of massive nuclei (ex. Uranium-235) Nuclear fusion: two isotopes of smaller size or forced together until they fuse (only happens at EXTREMELY high temperatures).

We Cannot Create or Destroy Matter Atoms can only be rearranged through reactions and changes, never destroyed or created Law of conservation of matter: when a physical or chemical change occurs, no atoms are created or destroyed Everything we think we have thrown away remains here with us in some form.

What Is Energy and How Can It Be Changed? When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed (first law of thermodynamics. Whenever energy is changes from one form to another, we end up with lower-quality and less usable energy than we started with (second law of thermodynamics).

Energy Comes in Many Forms Energy: capacity to do work or transfer heat Kinetic energy: Movement Ex. Wind, flowing water, electricity Heat Radiation, conduction, convection Electromagnetic radiation Gamma rays, X rays, UV rays, etc. Potential energy: Stored energy Ex. Piece of coal.

Some Types of Energy Are More Useful Than Others Energy quality is a measure of an energy source’s capacity to do useful work High quality vs. low quality.

Energy Changes Are Governed by Two Scientific Laws Law of conservation of energy (aka first law of thermodynamics) When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed Energy input = energy output Second Law of thermodynamics When energy changes from one form to another, we always end up with lower-quality or less usable energy than we started with Second form of energy is usually heat.

What Are Systems and How Do They Respond to Change? Systems have inputs, flows and outputs of matter and energy, and their behavior can be affected by feedback. Life, human systems and the earth’s life-support systems must conform to the law of conservation of matter and the two laws of thermodynamics.

Systems have inputs, flows, and outputs System: set of components that function and interact in some regular way Ex. Human body, river, etc.

Systems respond to change through feedback loops Feedback: any process that increases (positive feedback) or decreases (negative feedback) a change to a system Positive: Pressure on the opening of the uterus results in increased contractions during childbirth Negative: Sweating when your body temperature gets too high Feedback loops occur when an output of matter, energy or information is fed back into the system as input.

System effects can be amplified through synergy Synergy occurs when two or more processes interact so that the combined effect is greater than the sum of their separate effects “The whole is greater than the sum of its parts.” Ex. Smoking, asbestos and lung cancer

Human activities can have unintended harmful effects Everything that we do affects someone or something in the environment in some way Complex systems  unpredictable Ex. Clearing the Amazon rain forest for agricultural use.