Question

this particle can travel faster than the speed of light.
jellium
quantum dots
tachyons
question 2
1 pts
the world’s official kilogram is a two - inch - wide, 90% ______ cylinder that, by definition, has a mass of exactly 1.000000...kilogram.
caesium
chromium
platinum

Explanation:

1. For the first question: Tachyons are hypothetical particles theorized to travel faster than the speed of light, while jellium is a model for electron systems and quantum dots are semiconductor nanocrystals with no superluminal properties.
2. For the second question: The original international prototype of the kilogram was a cylinder made of 90% platinum and 10% iridium, matching the description provided. Caesium is used for atomic clocks, and chromium is not the material for this standard.

Answer:

1. tachyons
2. platinum