After 2 half-lives there will be 25% of the original isotope, and 75% of the decay product. After 3 half-lives there will be 12.5% of the original isotope, and 87.5% of the decay product. After 4 half-lives there will be 6.25% of the original isotope, and 93.75% of the decay product.
The tendency for water molecules to stick together causes it to causes spheres in space. ... Magnetic-like molecules on water's surface cause the surface to behave like an elastic skin. Each molecule is pulled with equal tension by its neighbors.J
