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化学是以实验为基础的学科,在实验中,不仅要准确的测定数据,还要正确的记录和运算,在计算和记录数据时,取几位有效数字尤为重要.近几年的高考对有效数字的使用也作了要求,本文就对有效数字及应用作简单介绍. 一、有效数字的概念及位数 1.概念: 有效数字是指在分析工作中实际能测量到的数字,在这个数字中,最后一位不是很准确的,是“不定数字”,而其余各位数字都是准确的.测量结果取几位有效数字由测量方法和仪器的精确度来决定.
Chemistry is a discipline based on experiments. In experiments, not only accurate data must be measured, but also correct records and calculations. When calculating and recording data, it is particularly important to take several significant figures. In recent years, the college entrance examination is effective. The use of numbers is also required. This article gives a brief introduction to effective figures and applications. First, the concept of effective numbers and the number of digits 1. Concept: The effective number refers to the number actually measured in the analysis work, in this figure The last one is not very accurate. It is an “indefinite number” and the remaining digits are all accurate. Several valid figures for the measurement result are determined by the accuracy of the measurement method and the instrument.