Question

一些化学题目 英文版 的

1 A piece of wood has a labeled length calue of 76.49 cm. You measure its length three times and record the following data:76.48cm 76.47cm and 76.59cm. How many significant figures do these measurements have?
2Are the measurements in problem 39 accurate? Are they precise? Explain your answers.
3Calculate the percent error for each measurement in problem 39
4Round 76.51cm to two significant figures.Then round your answer to one significant figure.
5 Which of these measurements was made with the most precise measuring device:8.1956m,8.20m,or 8.196m? Explain you answer.
6Write an expression for the quantity 506000 cm in which it is clear that all the zeros are significant
急求答案 最好中英文双解哈 谢谢了 答的好分数 会多给的

Answer 1

1. 76.48cm has 4 significant figures
76.47cm has 4 significant figures
76.59cm has 4 significant figures

2. the measurements in problem 39 is not accurate because it is off by 1mm ~ 10 mm; they are not precise also, because to be precise the unit of measurement has to be the smallest and biggest number

3. % error = (estimate - actual) / actual * 100 in absolute value
% of error for 76.48cm is 0.0126%
% of error for 76.47cm is 0.0262%
% of error for 76.59cm is 0.1306%

4. Round to 2 significant figures: 77; round to 1 significant figure: 100

5. 8.1956m because it's up to the ten-thousandth digit

6. 506000.00cm

我不会中文的。。Is this 10th grade chemistry questions? By the way, I'm not in chemistry so the answers that I have might be wrong.