Plutonium is much rarer in nature than uranium and is more commonly used for bombs rather than as reactor fuel. Like uranium, it comes in various isotope forms, with plutonium 239 the most commonly used. It is mixed with the much more unstable plutonium 240 to generate power.
It's my understanding that a horse's knees close around age 2- 2 1/2. My gelding JUST turned 3. A couple days ago in fact. Will a horse's knees almost certainly be closed by that age?
By three months of age, the anterior fontanel is closed in 1 percent of infants; by 12 months, it is closed in 38 percent; and by 24 months, it is closed in 96 percent. Anterior fontanels tend to close earlier in boys than in girls; the initial size of the fontanel is not a predictor of when it will close.19