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Sep 20, 2022 · There are 10 millimeters in 1 centimeter and 100 centimeters in 1 meter. Metric prefixes are used to distinguish between units of different size. These prefixes all derive from either Latin or Greek terms. For example, mega comes from the Greek word μεγας μ ε γ α ς, meaning "great". Table 3.2.1 3.2. 1 lists the most common metric ...
- Scientific Notation
Scientific notation is a way to express numbers as the...
- Si Base Units
SI Base Units. All measurements depend on the use of units...
- Scientific Notation
The number of protons plus the number of neutrons in the nucleus of an atom is called its ___. mass number. The ___ is a weighted average of the relative atomic masses of all the isotopes of an element. atomic mass. An atom with the same number of protons but a different number of neutrons is called a (n) ___. isotope.
The International System of Units is a system of measurement based on the metric system. The acronym SI is commonly used to refer to this system and stands for the French term, Le Système International d'Unités. The SI was adopted by international agreement in 1960 and is composed of the seven base units in Table 2.5.1.
The standard volume is a cubic meter (m 3), a cube with an edge length of exactly one meter. To dispense a cubic meter of water, we could build a cubic box with edge lengths of exactly one meter. This box would hold a cubic meter of water or any other substance. A more commonly used unit of volume is derived from the decimeter (0.1 m, or 10 cm).
- Section 1: Chemistry and Matter
- Section 2: How Scientists Study Chemistry
- Section 3: Scientific Notation
- 103 = 1000 104 = 10000 105 = 100000
- 579, 000, 000, 000
- Coefficient Is: 5.79
- How Many Positions Are there?
- 4 = 0.0001 10-5 = 0.00001
- Coefficient Will Be 6.42
- How Many positions?
What is Chemistry?
Everything around us is made up of chemicals. From the color that makes a rose so red to the gasoline that fills our cars and the silicon chips that power our computers and cell phones…Chemistry is everywhere! Understanding how chemical molecules form and interact to create complex structures enables us to harness the power of chemistry and use it, just like a toolbox, to create many of the modern advances that we see today. This includes advances in medicine, communication, transportation, b...
Physical vs. Chemical Properties
Part of understanding matter is being able to describe it. One way chemists describe matter is to assign different kinds of properties to different categories. The properties that chemists use to describe matter fall into two general categories. Physical properties are characteristics that describes matter, such as boiling point, melting point and color. Physical Changes, such as melting a solid into a liquid, do not alter the chemical structure of that matter. Chemical properties are charact...
Elements and Compounds
Any sample of matter that has the same physical and chemical properties throughout the sample is called a substance. There are two types of substances. A substance that cannot be broken down into chemically simpler components is an element. Aluminum, which is used in soda cans, is an element. A substance that can be broken down into chemically simpler components (because it has more than one element) is a compound. Water is a compound composed of the elements hydrogen and oxygen. Today, there...
The Scientific Method
How do scientists work? Generally, they follow a process called the scientific method. The scientific method is an organized procedure for learning answers to questions. To find the answer to a question (for example, “Why do birds fly toward Earth’s equator during the cold months?”), a scientist goes through the following steps, which are also illustrated in Figure 1.7. Figure 1.7 The General Steps of the Scientific Method.The steps may not be as clear-cut in real life as described here, but...
The study of chemistry can involve numbers that are very large. It can also involve numbers that are very small. Writing out such numbers and using them in their long form is problematic, because we would spend far too much time writing zeroes, and we would probably make a lot of mistakes! There is a solution to this problem. It is called scientifi...
As you can see, the power to which 10 is raised is equal to the number of zeroes that follow the 1. This will be helpful for determining which exponent to use when we express numbers using scientific notation. Let us take a very large number:
and express it using scientific notation. First, we find the coefficient, which is a number between 1 and 10 that will be multiplied by 10 raised to some power.
This number will be multiplied by 10 that is raised to some power. Now let us figure out what power that is. We can do this by counting the number of positions that stand between the end of the original number and the new position of the decimal point in our coefficient.
We can see that there are 11 positions between our decimal and the end of the original number. This means that our coefficient, 5.79, will be multiplied by 10 raised to the 11th power. Our number expressed in scientific notation is:
The number of spaces to the right of the decimal point for our 1 is equal to the number in the exponent that is behind the negative sign. This is useful to keep in mind when we express very small numbers in scientific notation. Here is a very small number:
This number will be multiplied by 10 raised to some power, which will be negative. Let us figure out the correct power. We can figure this out by counting how many positions stand between the decimal point in our coefficient and the decimal point in our original number.
There are 5 positions between our new decimal point and the decimal point in the original number, so our coefficient will be multiplied by 10 raised to the negative 5th power. Our number written in scientific notation is:
British thermal unit (Btu), defined as the amount of thermal energy required to raise the temperature of one pound of water by one degree Fahrenheit. 1 Btu = 1055.06 J = 0.252 kcal = 1055.06 J. 1 Btu = = 2.931 x 10-4 kWh (household electrical energy) kcals in food. 1 gram of each:
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We will use most of the fundamental units in chemistry. Initially, we will deal with three fundamental units. The metre (m) is the SI unit of length. It is a little longer than a yard (see Figure 2.4 “The Metre”). The SI unit of mass is the kilogram (kg), which is about 2.2 pounds (lb).
