Apound is approximately 0.45 kilogram. a person weighs 87 kilograms. what is the person’s weight, in pounds, when expressed to the correct number of significant figures?

Explanation: Given 0.45 kg = 1 pound

Thus if 0.45 kg is equal to= 1 pound

87 kg will be equal to=

The number of significant digits in an answer should be equal to the least number of significant digits in any one of the numbers being multiplied, divided etc. Thus the answer should contain 2 significant digits.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.