Question

B. Round off each of the following
quantities to two significant figures :
a. 25.55 mL
b. 0.00254 m
c. 1.491 x 105 mg d. 199 g​

Answer 1

Answer:

round Off

a.26

b.25.4

c. 16

d.20

Answer 2

Answer:a.  $2.6\times 10^1$

b. 0.0025

c.  $1.5\times 10^5$

d. $2.0\times 10^2$

Explanation:

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Scientific notation : It is defined as the way or representation of expressing the number that are too big or too small that is written in the decimal form. That means always written in the power of 10 form.

For example : 700 is written as, $7\times 10^2$  

a. 25.55 ml is written as $2.6\times 10^1$ in 2 significant digits.

b.  0.00254m is written as 0.0025 in 2 significant digits.

c. $1.491\times 10^5$ mg is is written as $1.5\times 10^5$

d.  199 g is  written as $2.0\times 10^2$ in 2 significant digits.