PLEASE HEL: Radioactive Decay Rate

Amount of Radioactive Sample

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

Part 2: How long would it take 308 g of the sample to decay to 4.8125 grams? Show your work or explain your answer.

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.

What are several ways to reduce the effect of friction

Why do electrons further from the nucleus have more energy