Plutonium-238 has a half life of 87.7 years. What percentage of a 5 kilogram (kg) sample remains after 50 years?

Which of the following would not be taken into consideration when describing the quality of a sound

Janelle made a hypothesis bout the uneven temperatures inside her house during winter. she believes that 50% of the ducts are blocked and she plans to investigate. if she wants to prove her hypothesis using scientific processes what should she do next?

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.