I'm not sure what your question is. But, the half life is the amount of time required for half the material to decay. For U238 this is 4.5 billion years, whilst for Fr-223 (Francium) its about 22 minutes. To calculate the time for something to decay you need to use the equation:
Mass (after time t) = Mass (initial) * (0.5)^(time/half life)
Hope this helps
<span>Mitosis is a a means for cells to split and produce exact copies of themselves. The process produces two identical copies of the original cell and occurs throughout the human body. Mitosis is divided up into four main phases known as prophase, metaphase, anaphase and telophase. The chromosomes first become visible in early prophase.</span>
An average facility manager can build one new facility
during his or her career.
<span>A </span>facilities manager<span> is the ultimate organiser, making sure that a
workplace meets the needs of employees by managing all of the required
services. In this job, you will be responsible for the </span>management<span> of services and processes that support the core
business of an organisation.</span>
