It has the same number of protons, otherwise it wouldn't be uranium.
The formula for the fraction remaining is one-half raised to the power given by the number of years divided by the half-life (in other words raised to a power equal to the number of half-lives).
Within the nucleus, we find neutrons and protons; but for now, let's just focus on the neutrons.
These neutrons can become unstable, and when they do, they release energy and undergo decay. Radioactivity occurs when the nucleus contains an excess amount of neutrons.
However, Mt Ngauruhoe is an imposing, almost perfect cone that rises more than 1,000 metres (3,300 feet) above the surrounding landscape to an elevation of 2,291 m (7,500 feet) above sea level (Figure 3).
Eruptions from a central 400 m (1,300 foot) wide crater have constructed the cone’s steep (33°) outer slopes.