Which of the measurement contain three significant figure?

The answer is explained below

Explanation:

The question is not complete.

The correct question should be like:

Which of the measurement contain three significant figure?

500

395

0.001

0.00100

1 × 10⁻³

5 × 10²

The following are rules applied when considering significant figures:

i) All digits are significant excluding zero. E.g of significant digits are 1,2,3,4,5,6,7,8,9

ii) Any zero that appear within or after non zero digits are significant e.g. 200, 1004, 500009

iii) Zeros before non zero digits are not significant. An example shows significant digits bolded 001,  0.0012, 001.56

iv) Zeros that come after non zero digits are significant even if the number is in decimal form. An example shows significant digits bolded 1000,  0.001200, 001.5600

Therefore:

500: It contains three significant digits

395: It contains three significant digits

0.001:  It contains only one significant digits

0.00100: It contains three significant digits

1 × 10⁻³: 1 × 10⁻³ = 0.001.  It contains only one significant digits

5 × 10²: 5 × 10² = 500. It contains three significant digits

The measurements that contain three significant figure are 500, 395, 0.00100 and 5 × 10²

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.