The half-life of plutonium-238 is 87.7 years. what percentage of the atoms in a sample of plutonium-238 will remain radioactive after 263.1 years? % what percentage of the atoms in the same sample of plutonium-238 will have changed to another isotope after 263.1 years?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.

Select all the correct answers. which three statements about electromagnetic radiation are true?