Question

Significant Figure Questions 1. How many significant figures are in each of the following numbers? 2430 0.0251 3 1.010 x 10 243.0 0.0040 900.0 243 7063.1 2.7000 5.98 x 103 2. Using standard scientific notation express 0.14503 meters in: em with 2 signíficant figures km with 4 significant figures 3. Express the following in scientific notation: 6795 to three significant figures 0.42885 to four significant figures

Answer 1

The significant figures means the meaningful digits in that number.

243 : Three significant figures.

2430 : four significant figures.

243.0 : four significant figures. ( any number if we start with a non gero integer we count all the geros present in that number).

7063.1 : seven significant figures.

0.0251 : Three significant figures ( if a decimal number start with gero, the geros present upto starting of the non gero integer we don't count, and after the starting of the non gero integer all the geros will be counted.

0.0041 : Two significant figures.

2.7000 : five significant figures.

3 : one significant figure.

900.0 : four significant figures.

5.98 x 10^-3 : three significant figures.

1.010 x 10⁴ : four significant figures.

Question 2:

0.14503 metres can be written as = 1.4503 x 10^-1metres.  The number of significant figures = five.

In cms

= 1.4503 x 10^-3 cm (one cm = 10^-2 metres).

In kilometres

= 1.4503 x 10^-4 km ( one metre = 10^-3 km).

Question 3:

6795 scientific notation is 6.795 x 10³ (there are four significant figures, it can't be rounded of to three significant figures).

0.42885 rounded of to four significant figures

= 0.4288

The scientific notation = 4.288 x 10^-1

Scientific notation = N x 10ⁿ

N must be present in between 1 an 10 and it can decimal point also.

n must be an integer can be negative or positive.