Silicates are minerals that contain silicon atoms bonded to oxygen atoms. The basic building block for all silicate minerals is called a tetrahedron, where one silicon atom is bonded to 4 oxygen atoms (Figure 3.6). Silicate minerals also often contain other elements, such as calcium, iron, and magnesium.hosphates have a tetrahedron building block that is similar to that of the silicates. But, instead of silicon, phosphates have an atom of phosphorus, arsenic, or vanadium bonded to oxygen. Although there are many minerals in this group, most of the minerals are rare.
Neptune is the coldest planet in the Solar System. At the top of its clouds, temperatures on Neptune can dip down to 51.7 Kelvin, or -221.4 degrees Celsius. Thatâs cold! Pluto gets colder, but then, Pluto isnât a planet any more.
Neptune is the eighth and farthest planet from the Sun in the Solar System. It is the fourth-largest planet by diameter and the third-largest by mass. Among the giant planets in the Solar System, Neptune is the most dense.Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth, and not as dense as Neptune.ecause of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching 55 K (â218 Â°C). Temperatures at the planet's centre are approximately 5,400 K (5,100 Â°C).