You've just solved a problem and the answer is the mass of an electron, me=9.11×10−31kilograms. how would you enter this number into the answer box?
enter your answer in kilograms using three significant figures. note that the units are provided for you to the right of the answer box.

The mass of an electron, me, 9.11 × 10⁻³¹ kilograms shows there are 3 important numbers in them, namely numbers 9, 1, and 1

Significant numbers are obtained from measurement results of exact numbers and the last number estimated

This is called significant numbers

the scientific notation can be described as:

a, ... x 10ⁿ

a, ... called a significant number

10ⁿ is called a big order

Rules for significant numbers in general:

From the numbers known in the question amounting to 9.11 × 10⁻³¹ kilograms shows there are 3 important numbers in them,(symbol a, before a big order ,called a significant number) namely numbers 9, 1, and 1

significant figures

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significant figures in the following number: 5.67 x 106

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the number of significant figures is 0.025

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0.080 significant figures

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the fewest number of significant figures

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Keywords : significant number, the scientific notation, decimal point, a big order

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.