He table shows the amount of radioactive element remaining in a sample over a period of time. Radioactive Decay Rate
Amount of Radioactive Sample
(grams) Time
(years)
56.0 0
47.1 400
39.6 800
33.3 1,200
28 1,600

Part 1: What is the half-life of the element? Explain how you determined this.
Part 2: How long would it take 312 g of the sample to decay to 9.75 grams? Show your work or explain your answer.
Source
StylesNormal

On a distance vs time graph the line of an object at rest is a

What is a scientific theory? a. a scientist's guess about how something works b. the results of an experiment obtained using the scientific method c. a proven fact that will never change d. an idea that is backed by data from many sources

Two people each hold the end of a rope and create waves by moving their arms up and down. this wave is best classified as a transverse wave because a) both the rope particles and the wave are moving in the same direction. b) the wave is moving up and down as the particles of the rope move horizontally. c) the wave is moving horizontally as the particles of the rope move up and down. eliminate d) the wave is moving in a parallel direction with the motion of the person's arms.