Chapter 2 Answers

Chapter 2: Science, Matter, and Energy

1. How science works: based on assumption that events in nature world follow cause-effect patterns, can be understood with observation and experimentation; To figure out these patterns, scientists first ask questions, then do experiments and collect data. After interpreting the data, well-tested and accepted patterns in data become scientific laws. If the data cannot be considered a law, a hypothesis is formed to explain the data. More experiments are done to test the hypothesis so that well tested and accepted hypothesis can become a scientific theory.
Scientific Method: There are many different ways in which scientists gather data and formulate and test scientific hypothesis, models, theories, and laws - these ways are called scientific methods. Most scientists conduct controlled experiments to isolate and study a variable that influences a part of nature that the scientist wants to understand. This isolated variable becomes part of the experimental group that is changed in some way; a control group also exists to compare the isolated variable.

2. Science: attempt to discover order in nature and use that knowledge to make predictions about what is likely to happen in nature
Frontier Science: preliminary and untested data and hypotheses - often controversial because they haven't been widely tested and accepted
Consensus Science: (also called sound science) consists of data, theories, and laws that are widely accepted by scientists who are considered experts in the field

3. Environmental science: interdisciplinary study that uses info from the physical sciences and social sciences to learn how the earth works, how we interact with the earth, and how to deal with environmental problems.
Possible problems with using science to address environmental problems: unlike other sciences, environmental problems don’t always follow distinct cause-effect patterns; generally speaking, environmental problems are caused by lots of things and produce many side effects. This science is not always black and white.
Model: an approximate representation or simulation of a system being studied used to test a hypothesis - may be a working, mental, pictorial, computer, or a mathematical model
-(Amanda Groves, Period 5)

7. The first law of theromodynamics ( law of conservation of energy): in all physical and chemical changes, energy is neither created nor destroyed, although it may be converted from one form to another.
The second law of thermodynamics: when energy changes from one form to another, some of the useful energy changes from one form to another, some of the useful energy is always degraded to lower-quality, more dispersed less useful energy.

8. The first law dictates that energy input is always equal to energy output, and we “cannot get something for nothing in terms of energy quantity.” The second law says that we cannot break even in terms of energy quality because energy goes from a more useful form to a less useful form. This means, that when we drive a car, gasoline is being converted into mechanical energy and electrical energy, and energy is lost. By discovering more efficient light filaments, we can conserve energy by reducing energy lost. Also, in living systems, 10% of energy is lost to each level, first solar energy into chemical energy then to mechanical energy.
9. Most of the most developed societies today are high- throughput/ waste societies. They boost economic growth by increasing the one-way flow of matter and resources through their economic systems. Matter-recycling- and reuse economy are economies that recycle and reuse. The change to this type of society will take time, but it is ultimately the only society that will thrive infinitely. A more sustainable low-waste society means building the concept of recycling and reusing as much matter as possible by also reducing the throughput of matter and energy through an economy. We need to waste less matter and energy, live more simply, slow population growth. We need to live by the two laws of thermodynamics.

(Ranae Jabri, 5th Period, APES)


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