SI Measurement System Chart

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The International System of Units (SI) is made up of 7 base units, featured on this chart with their Measurement League counterparts. The SI, commonly known as the metric system, is easy to use. KILOGRAM (kg) MASS KELVIN (K) TEMPERATURE The kilogram is the unit of mass, The kelvin, unit of thermodynamic equal to the mass of the international temperature, is the fraction 1/273.16 of the prototype of the kilogram (IPK). thermodynamic temperature of the triple point of water. CANDELA (cd) AMPERE (A) LUMINOUS INTENSITY ELECTRIC CURRENT The candela is the luminous The ampere is that constant intensity, in a given direction, current which, if maintained of a source that emits in two straight parallel monochromatic radiation conductors of infinite length, of frequency 540 x 1012 of negligible circular cross hertz and that has a radiant section, and placed 1 meter intensity in that direction of apart in vacuum, would RDIANS OF TH 1/683 watt per steradian. GUA E SI produce between these conductors a force equal to 2 x 10-7 newton per meter of length. METER (m) LENGTH The meter is the length of the path traveled by light in vacuum during a time interval MOLE (mol) of 1/299 792 458 of a second. AMOUNT OF SUBSTANCE The mole is the amount of substance SECOND (s) TIME of a system which contains as many The second is the duration of elementary entities as there are 9 192 631 770 periods of the radiation atoms in 0.012 kilogram of carbon 12. corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. 1 1 1 1 PREFIXES 1 1 This publication 1 01 is free of charge 1 000 00 000 00 000 00 1 000 00 000 00 000 00 000 00 1 000 1 000 1 000 1 000 0. 0. 0. 0. 1 000 1 000 1 0. 1 000 100 10 0.0 0.0 0. 0. 1 000 from: https://doi. 0. org/10.6028/NIST. 10 24 10 21 10 18 10 15 10 12 10 9 10 6 10 3 10 2 10 1 10 0 10 -1 10 -2 10 -3 10 -6 10 -9 10 -12 10 -15 10 -18 10 -21 10 -24 SP.304a-2017 YZEPTGMk hdadc m µ npfazy i a a a a o o o o o ra to nt tt ct ex kilo te ett atto deci milli pic giga peta ept dek ce nano z yo mega yo hec z micr NIST SP 304A femt July 2017 SI symbols are the same worldwide, regardless of the spelling, language, [email protected] www.nist.gov/metric or alphabet. Prefix symbols are used with a unit symbol to represent smaller or larger units by factors that are powers of 10. www.nist.gov.

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About SI Units
Units SI units: International system of units (French: “SI” means “Système Internationale”) The seven SI base units are: Mass: kg Defined by the prototype “standard kilogram” located in Paris. The standard kilogram is made of Pt metal. Length: m Originally defined by the prototype “standard meter” located in Paris. Then defined as 1,650,763.73 wavelengths of the orange-red radiation of Krypton86 under certain specified conditions. (Official definition: The distance traveled by light in vacuum during a time interval of 1 / 299 792 458 of a second) Time: s The second is defined as the duration of a certain number of oscillations of radiation coming from Cs atoms. (Official definition: The second is the duration of 9,192,631,770 periods of the radiation of the hyperfine- level transition of the ground state of the Cs133 atom) Current: A Defined as the current that causes a certain force between two parallel wires. (Official definition: The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 Newton per meter of length. Temperature: K One percent of the temperature difference between boiling point and freezing point of water. (Official definition: The Kelvin, unit of thermodynamic temperature, is the fraction 1 / 273.16 of the thermodynamic temperature of the triple point of water. Amount of substance: mol The amount of a substance that contains Avogadro’s number NAvo = 6.0221 × 1023 of atoms or molecules.
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Guide for the Use of the International System of Units (SI)
Guide for the Use of the International System of Units (SI) m kg s cd SI mol K A NIST Special Publication 811 2008 Edition Ambler Thompson and Barry N. Taylor NIST Special Publication 811 2008 Edition Guide for the Use of the International System of Units (SI) Ambler Thompson Technology Services and Barry N. Taylor Physics Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899 (Supersedes NIST Special Publication 811, 1995 Edition, April 1995) March 2008 U.S. Department of Commerce Carlos M. Gutierrez, Secretary National Institute of Standards and Technology James M. Turner, Acting Director National Institute of Standards and Technology Special Publication 811, 2008 Edition (Supersedes NIST Special Publication 811, April 1995 Edition) Natl. Inst. Stand. Technol. Spec. Publ. 811, 2008 Ed., 85 pages (March 2008; 2nd printing November 2008) CODEN: NSPUE3 Note on 2nd printing: This 2nd printing dated November 2008 of NIST SP811 corrects a number of minor typographical errors present in the 1st printing dated March 2008. Guide for the Use of the International System of Units (SI) Preface The International System of Units, universally abbreviated SI (from the French Le Système International d’Unités), is the modern metric system of measurement. Long the dominant measurement system used in science, the SI is becoming the dominant measurement system used in international commerce. The Omnibus Trade and Competitiveness Act of August 1988 [Public Law (PL) 100-418] changed the name of the National Bureau of Standards (NBS) to the National Institute of Standards and Technology (NIST) and gave to NIST the added task of helping U.S.
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2.1.3 Amount of Substance the Mole Is the Key Concept for Chemical Calculations
2.1.3 Amount of substance The mole is the key concept for chemical calculations DEFINITION: The mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon-12. DEFINITION: Relative atomic mass is the average mass of one atom compared to one twelfth of the mass of one atom of carbon-12 DEFINITION: Molar Mass is the mass in grams of 1 mole of a substance and is given the unit of g mol-1 Molar Mass for a compound can be calculated by adding up the mass numbers(from the periodic table) of each element in the compound eg CaCO3 = 40.1 + 12.0 +16.0 x3 = 100.1 molar gas volume (gas volume per mole, units dm3 mol–1) . This is the volume of 1 mole of a gas at a given temperature and pressure. All gases have this same volume. At room pressure (1atm) and room temperature 25oC the molar gas volume is 24 dm3 mol–1 Avogadro's Constant There are 6.02 x 1023 atoms in 12 grams of carbon-12. Therefore explained in simpler terms 'One mole of any specified entity contains 6.02 x 1023 of that entity': 1 mole of copper atoms will contain 6.02 x 1023 atoms Avogadro's Constant can be 1 mole of carbon dioxide molecules will contain 6.02 x 1023 molecules used for atoms, molecules and 1 mole of sodium ions will contain 6.02 x 1023 ions ions For pure solids, liquids and gases Example 1: What is the amount, in mol, in 35.0g of CuSO4? amount = mass amount = mass/Mr Mr = 35/ (63.5 + 32 +16 x4) Unit of Mass: grams = 0.219 mol Unit of amount : mol Many questions will involve changes of units 1000 mg =1g 1000 g =1kg 1000kg = 1 tonne Significant Figures Give your answers to the same number of significant figures as the Example 2: What is the amount, in mol, in 75.0mg of number of significant figures for the CaSO4.2H2O? data you given in a question.
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Properties of Matter
Properties of Matter Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable version of this book, as well as other interactive content, visit www.ck12.org CK-12 Foundation is a non-proﬁt organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the FlexBook®, CK-12 intends to pioneer the generation and distribution of high-quality educational content that will serve both as core text as well as provide an adaptive environment for learning, powered through the FlexBook Platform®. Copyright © 2013 CK-12 Foundation, www.ck12.org The names “CK-12” and “CK12” and associated logos and the terms “FlexBook®” and “FlexBook Platform®” (collectively “CK-12 Marks”) are trademarks and service marks of CK-12 Foundation and are protected by federal, state, and international laws. Any form of reproduction of this book in any format or medium, in whole or in sections must include the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in addition to the following terms. Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution/Non- Commercial/Share Alike 3.0 Unported (CC BY-NC-SA) License (http://creativecommons.org/licenses/by-nc-sa/3.0/), as amended and updated by Creative Commons from time to time (the “CC License”), which is incorporated herein by this reference.
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PHYSICS of Materials (PHYS132)
PHYSICS of Materials (PHYS132) Dr Sergey Burdin (Oliver Lodge, Room 314, [email protected]) (based on earlier lectures by Prof. R. McGrath and Dr Joost Vossebeld) 7 topics (13 lectures) • Introduction: definitions, structure (2) • inter-atomic forces (2) • Thermal properties: States of matter, latent heat, thermal expansion (3) • Mechanical properties: elasticity (1) • Magnetic properties (2) • Electrical properties: band theory, semi-conductors (2) • Optical properties: colour (1) 3 question sheets: 10% of final mark for satisfactory submission. Fairly difficult but good practice for exam. 6 weeks × 3 hours – 1 = 17 hours (13 lectures + 3 problem sessions + 1) 1. Introduction to Materials > 1.1 Definitions 1 PHYSICS of Materials PHYS132 Books: (recommended, not required) Fundamentals of Physics (Haliday, Resnick, Walker): Electrical and magnetic properties of matter Properties of Matter (Flowers and Mendoza): Structure, interatomic potentials, thermal properties, mechanical properties Gases, Liquids and Solids (Tabor): Structure, interatomic potentials, thermal properties Properties of Materials (White): Optical properties 1. Introduction to Materials > 1.1 Definitions 2 PHYSICS of Materials PHYS132 General approach: Start with: MICROSCOPIC properties of matter: Structure of materials. Forces between atoms, molecules, ions. (Atomic Physics & Chemistry) To arrive at: MACROSCOPIC properties of matter: density, elasticity, latent heat, conductivity, etc. (Material science, Engineering, Applied physics) 1. Introduction to Materials > 1.1 Definitions 3 Section 1. Introduction to materials Topic 1.1 Definitions Atoms, Molecules, Ions. Mole, Molar Mass, Atomic mass Few example calculations §1. Introduction to Materials > 1.1 Definitions 4 Atoms, ions and molecules Macroscopic matter is made up of assemblies of atoms, ions and molecules He ATOMS n n The smallest particle of an ELEMENT consists of p p NUCLEUS (Z Protons + N Neutrons) surrounded by Z Electrons.
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The International System of Units (SI)
NAT'L INST. OF STAND & TECH NIST National Institute of Standards and Technology Technology Administration, U.S. Department of Commerce NIST Special Publication 330 2001 Edition The International System of Units (SI) 4. Barry N. Taylor, Editor r A o o L57 330 2oOI rhe National Institute of Standards and Technology was established in 1988 by Congress to "assist industry in the development of technology . needed to improve product quality, to modernize manufacturing processes, to ensure product reliability . and to facilitate rapid commercialization ... of products based on new scientific discoveries." NIST, originally founded as the National Bureau of Standards in 1901, works to strengthen U.S. industry's competitiveness; advance science and engineering; and improve public health, safety, and the environment. One of the agency's basic functions is to develop, maintain, and retain custody of the national standards of measurement, and provide the means and methods for comparing standards used in science, engineering, manufacturing, commerce, industry, and education with the standards adopted or recognized by the Federal Government. As an agency of the U.S. Commerce Department's Technology Administration, NIST conducts basic and applied research in the physical sciences and engineering, and develops measurement techniques, test methods, standards, and related services. The Institute does generic and precompetitive work on new and advanced technologies. NIST's research facilities are located at Gaithersburg, MD 20899, and at Boulder, CO 80303.
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Chapter 11: Gases
CHAPTER 11 GASES t’s Monday morning, and Lilia is walking out of the chemistry building, thinking 11.1 Gases and Their about the introductory lecture on gases that her instructor just presented. Dr. Properties Scanlon challenged the class to try to visualize gases in terms of the model she described, so Lilia looks at her hand and tries to picture the particles in the air 11.2 Ideal Gas Calculations bombarding her skin at a rate of 1023 collisions per second. Lilia has high hopes that a week of studying gases will provide her with answers to the questions her older brothers 11.3 Equation and sisters posed to her the night before at a family dinner. Stoichiometry and When Ted, who is a mechanic for a Formula One racing team, learned that Lilia Ideal Gases was going to be studying gases in her chemistry class, he asked her to find out how to 11.4 Dalton’s Law of calculate gas density. He knows that when the density of the air changes, he needs to Partial Pressures adjust the car’s brakes and other components to improve its safety and performance. John, who is an environmental scientist, wanted to be reminded why balloons that carry his scientific instruments into the upper atmosphere expand as they rise. Amelia is an artist who recently began to add neon lights to her work. After bending the tubes into the desired shape, she fills them with gas from a high pressure cylinder. She wanted to know how to determine the number of tubes she can fill with one cylinder.
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Chapter 16. a Macroscopic Description of Matter Chapter 16. A
10/12/10 Chapter 16. A Macroscopic Description of Chapter 16. A Macroscopic Description of Matter Matter Macroscopic systems are characterized as being either Topics: solid, liquid, or gas. These • Solids, Liquids, and Gases are called the phases of • Atoms and Moles matter, and in this chapter Temperature we’ll be interested in when • and how a system changes • Phase Changes from one phase to another. • Ideal Gases Chapter Goal: To learn the • Ideal-Gas Processes characteristics of macroscopic systems. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. State Variables Density The ratio of a system’s mass to its volume is called the • Parameters for macroscopic description of mass density, or sometimes simply “the density.” matter • Volume, pressure, mass, mass density, thermal energy, moles, number density, temperature The SI units of mass density are kg/m3. In this chapter we’ll use an uppercase M for the system mass and lowercase m for the mass of an atom. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Atoms and Moles • The mass of an atom is determined primarily by its most massive constituents, the protons and neutrons in its nucleus. • The sum of the number of protons and neutrons is called the atomic mass number A. • The atomic mass scale is established by defining the mass of 12C to be exactly 12 u, where u is the symbol for the atomic mass unit. • The conversion factor between atomic mass units and kilograms is Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.
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8-1 SECTION 8 AMOUNT of SUBSTANCE and ITS UNIT, the MOLE Amount of Substance: Symbol N, a Quantity Fundamental to Chemistry
8-1 SECTION 8 AMOUNT OF SUBSTANCE AND ITS UNIT, THE MOLE Suppose a chemist wishes to carry out the chemical reaction of adding bromine to hexene to give dibromohexane, C6H12 + Br2 → C6H12Br2, starting with a known amount of hexene. How does the chemist know how much bromine is needed? The chemical equation tells you that one molecule of dibromine is needed for each molecule of hexene. But the very large numbers of molecules required for reactions on a practicable scale cannot be counted. If the mass of hexene is known how could the mass of bromine required be calculated? This section tells how this type of question is answered. It requires the introduction of a new quantity specific to chemistry , amount of substance, and it it th l Amount of substance: symbol n, a quantity fundamental to chemistry. Atoms and molecules are much too small or light to be counted or weighed individually in the laboratory. The chemist therefore needs a unit to specify the quantity amount of substance of an appropriate magnitude (size) for laboratory or industrial scale work. The chosen unit is the mole. Mole: symbol mol, the unit of the quantity amount of substance. The mole is defined as the amount of substance of a system which contains as many elementary entities as there are atoms in 12 grams of carbon-12 (i.e. carbon consisting only of the isotope 12C). 12 g is an easily measurable mass. When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles or specified groups of such particles.
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Amount of Substance and Its Unit – Mole- Connecting the Invisible Micro World to the Observable Macro World Part 2 (English, Mp4)
Amount of Substance and Its Unit – Mole- Connecting the Invisible Micro World to the Observable Macro World Part 2 (English, mp4) [MUSIC PLAYING] Instructor: Hi, everyone. Welcome back. I hope you had some fun watching the BLOSSOMS lesson, How Big is a Mole? Did you find an answer to the question about eating rice? Can you believe it? My estimate is that it would take about seven million years for the people on earth to eat one mole of rice. Was your estimate close to this range? Are you impressed with the incredible size of a mole, which is around 6.02 times 10 to the 23rd. This number also goes by the name of Avogadro's number. And now I want to tell you how it got that name. Avogadro's number is named after the early 19th century Italian scientist Amedeo Avogadro, who, in 1811, first proposed that equal volumes of gases under the same conditions contain the same number of molecules. This hypothesis proved useful in determining the atomic and the molecular weights, and eventually led to the concept of a mole. Many years later, the French physicist Jean Perrin proposed naming the constant in honor of Avogadro. But Dr. Avogadro himself, during his life, never saw this number that is now named after him. Avogadro's number, NA is equal to 6.02 times 10 to the 23rd, like any pure number is dimensionless, which means there is no unit attached to it. However, it also defines the mole. So we can express NA as 6.02 times 10 to the 23rd per mole.
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The `` Amount of Substance '' and Its Unit the `` Mole ''
The “ amount of substance ” and its unit the “ mole ” Rita Khanfour-Armalé To cite this version: Rita Khanfour-Armalé. The “ amount of substance ” and its unit the “ mole ”. ESERA 2015 Confer- ence, Aug 2015, Helsinki, Finland. hal-01861051 HAL Id: hal-01861051 https://hal.archives-ouvertes.fr/hal-01861051 Submitted on 15 Apr 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The « amount of substance » and its unit the « mole » Rita Khanfour-Armalé Introduction The ‘mole’ unit of the amount of substance is one of the fundamental concepts in quantitative chemistry. The ‘‘amount of substance’’ is a concept that has been a frequent subject of discussion among science education researchers (Staver and Lumpe, 1993; Furio´ et al., 2000). However, previous research has shown that because of its abstract nature and the anomalous evolution of the definition in scientific history, the mole is generally acknowledged to be one of the most perplexing concepts in chemistry teaching and learning (Fang, 2011). The concept of amount of substance and mole present difficulties to students because they are abstract (Dierks 1981) and there is a lack of understanding of the microscopic and macroscopic scales (Claesgens & Stacy 2003).
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Composition of Substances and Solutions 129
Chapter 3 Composition of Substances and Solutions 129 Chapter 3 Composition of Substances and Solutions Figure 3.1 The water in a swimming pool is a complex mixture of substances whose relative amounts must be carefully maintained to ensure the health and comfort of people using the pool. (credit: modification of work by Vic Brincat) Chapter Outline 3.1 Formula Mass and the Mole Concept 3.2 Determining Empirical and Molecular Formulas 3.3 Molarity 3.4 Other Units for Solution Concentrations Introduction Swimming pools have long been a popular means of recreation, exercise, and physical therapy. Since it is impractical to refill large pools with fresh water on a frequent basis, pool water is regularly treated with chemicals to prevent the growth of harmful bacteria and algae. Proper pool maintenance requires regular additions of various chemical compounds in carefully measured amounts. For example, the relative amount of calcium ion, Ca2+, in the water should be maintained within certain limits to prevent eye irritation and avoid damage to the pool bed and plumbing. To maintain proper calcium levels, calcium cations are added to the water in the form of an ionic compound that also contains anions; thus, it is necessary to know both the relative amount of Ca2+ in the compound and the volume of water in the pool in order to achieve the proper calcium level. Quantitative aspects of the composition of substances (such as the calcium-containing compound) and mixtures (such as the pool water) are the subject of this chapter. 130 Chapter 3 Composition
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