Αποτελέσματα Αναζήτησης
Learning Objectives. Explain the process of measurement and describe the three basic parts of a quantity. Describe the properties and units of length, mass, volume, density, temperature, and time. Recognize the common unit prefixes and use them to describe the magnitude of a measurement.
To identify the basic units of measurement of the seven fundamental properties. Describe the names and abbreviations of the SI base units and the SI decimal prefixes. Define the liter and the metric ton in these units. Explain the meaning and use of unit dimensions; state the dimensions of volume.
Chemistry primarily uses five of the base units: the mole for amount, the kilogram for mass, the meter for length, the second for time, and the kelvin for temperature. The degree Celsius ( o C) is also commonly used for temperature.
A derived unit is a type of measurement unit within the International System of Units (SI) that is formed by combining one or more of the seven fundamental base units. These units may either be dimensionless or can be obtained by multiplying the base units together. Table of Contents. Derived Unit Names and Symbols.
There are seven basic units in the SI system. Five of these units are commonly used in chemistry.
The International System of Units (SI): Base units. All other SI units can be derived from these, by multiplying together different powers of the base units. In the 2018 revision of the SI, the definitions of four of the SI base units – the kilogram, the ampere, the kelvin and the mole – were changed.
In the metric system, base units are used for length, mass, volume, time, temperature, energy, and the amount of substance. Later we will explain how to modify the base units with prefixes to express very large and small measurements.
