The table shows the amount of radioactive element remaining in a sample over a period of time. Radioactive decay
Amount of radioactive sample(grams) Time (hours)
186.0 0
147.0 7
117.0 14
93.0 21
23.3 63

Part 1: What is the half-life of the element? Explained how you determined this.

Part 2: How long would it take 320 g of the sample to decay to 2.5 grams? Show your work or explain your answer.

Which of these best describes an ionic bond?

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?