There were four basic materials that the Egyptians used to build the pyramids: limestone, pink granite, basalt, and alabaster. Each type of material had a diverse use. Limestone had, for the most part, two uses.
To answer your question: The useful lifespan of a CPU is about 3-4 years. My guess on the technical lifespan under full load is closer to 8-10 years if nothing else breaks and takes the CPU with it. The reasons: High Performance Computing Clusters usually keep the computers for 3-4 years.
The lithium-ion batteries used in most laptops have a typical lifespan of 300 to 500 charge/discharge cycles. Full discharge of your laptop's battery should be avoided to avoid shortening the lifespan. Under proper operating conditions, lithium-ion batteries will last two to three years.