Thoughts for Christien on making spheres

The challenge is to make an initial sphere, representing the mass of the Earth, and then a series of smaller spheres representing the relative masses of elemements within the Earth:

https://en.wikipedia.org/wiki/Earth#Chemical_composition

Earth's mass is approximately 5.97×1024 kg (5,970 Yg). It is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminum (1.4%), with the remaining 1.2% consisting of trace amounts of other elements. Due to mass segregation, the core region is estimated to be primarily composed of iron (88.8%), with smaller amounts of nickel (5.8%), sulfur (4.5%), and less than 1% trace elements.

From the above quote from the Wikipedia page we now have the relative percentages of elements that make up the Earth.

Assuming that you are going to use the same material for each sphere, the calculations are as follows:

1. Decide the size of the sphere representing the entire Earth. For this example, I'm going to say that the overall "Earth Sphere" has a radius of 50cm, making it 100cm in diameter.
2. The volume of this sphere can then be worked out by using the equation for the volume of a sphere, which approximates to: 0.5236 * d^3, in this case = 0.5236 * 100 * 100 * 100 = 523,600 cm^3
3. Let's work out the volume of a sphere of iron in this case, which should be 32.1% that off the "Earth Sphere": 523600 * 0.321 = 168075.6
4. Let's work out the diameter of a sphere of volume 168075.6, which we can do by dividing by 0.5236 and taking the cube root = 68.47cm diameter for the "Iron Sphere". NB, an online scientific calulator can be found here: https://duckduckgo.com/?t=ffab&q=calculator&ia=calculator#