Maybe you’re taking this course because chemistry is fundamental to understanding other natural sciences. Maybe it’s required for your medical or engineering major. Or maybe you just want to learn more about the impact of chemistry on society or even on a personal, everyday level. For example, were you awakened today by your alarm clock? In chemical terms, the sound of the alarm was created when molecules aligned in the liquid-crystal display of your clock and electrons fl owed to create a noise. You might have thrown off a thermal insulator of manufactured polymer (blanket) and jumped in the shower to emulsify fatty substances on your skin and hair with purifi ed water and formulated detergents. Perhaps you next adorned yourself in an array of pleasant-smelling pigmented gels, dyed polymeric fi bers, synthetic footwear, and metal-alloy jewelry. After a breakfast of nutrient-enriched, spoilage-retarded carbohydrates (cereal) in a white emulsion of fats, proteins, and monosaccharides (milk) and a cup of hot aqueous extract containing a stimulating alkaloid (coffee), you probably abraded your teeth with a colloidal dispersion of artifi cially fl avored, dental hardening agents (toothpaste), grabbed your portable electronic device containing ultrathin, microetched semiconductor layers powered by a series of voltaic cells (laptop), collected some objects made from processed cellulose and plastic, electronically printed with light- and oxygen-resistant inks (books), hopped in your hydrocarbon-fueled, metal-vinyl-ceramic vehicle, electrically ignited a synchronized series of controlled gaseous explosions (started your car), and took off for class!
But the true impact of chemistry extends much farther than the commercial products of daily life. The truth is that the most profound biological and environmental questions ultimately have chemical answers: How does an organism reproduce, grow, and age? What are the underlying explanations for health and disease? How can we sustain a planetary ecosystem in which plant, animal, and human populations thrive? Is there life on other worlds?
So, no matter what your reason for studying chemistry, you’re going to learn some amazing ideas. And, this course comes with a bonus for developing two mental skills. The first, common to all science courses, is the ability to solve problems systematically. The second is specific to chemistry, for as you comprehend its ideas, you begin to view a hidden reality, one fi lled with incredibly minute particles moving at fantastic speeds, colliding billions of times a second, and interacting in ways that allow your brain to translate fl uxes of electric charge into thoughts and that determine how all the matter inside and outside of you behaves. This chapter holds the keys to unlock and enter this new world. iN thiS chapter . . . We discuss some central ideas about matter and energy, the process of science, units of measurement, and how scientists handle data.
- We begin with fundamental concepts about matter and energy and their changes.
- A brief discussion of chemistry’s origins, including some major missteps, leads to an overview of how scientists build models to study nature.
- We examine modern units for mass, length, volume, density, and temperature and apply systematic chemical problem solving to unit conversions.
- We see that data collection always includes some uncertainty and examine the distinction between accuracy and precision.