What causes volcanoes? Geology
Volcano erupting Volcanoes are places where the plates of the Earth's surface have cracks in them, so that the very hot melted rocks that are under the tectonic plates bubble [...]
26
06, 2017
26
06, 2017
Different kinds of rocks
Granite rock There are three different kinds of rocks on Earth, and they form in very different ways. The first kind is igneous rock, which means "fire rocks". Igneous rocks [...]
26
06, 2017
What is quartz? Igneous rock
What is quartz? A chunk of white quartz What is quartz made of? Quartz is an igneous rock made out of molecules of silicon and oxygen atoms held together in [...]
26
06, 2017
What are igneous rocks? Volcanic stone
Igneous rocks: Obsidian tools What does "igneous" mean? Igneous means "fiery", and igneous rocks are rocks that were made by heating them up in a fire. Usually that fire is [...]
25
06, 2017
What is granite? Igneous rock
Granite rock What is granite? Granite forms when bits of quartz and feldspar shoot out of volcanoes, so it's one kind of igneous rock. What is quartz? Where does feldspar [...]
25
06, 2017
Feldspar rock – a kind of igneous rock
A feldspar rock quarry in India Is feldspar rare? Feldspar is a very common igneous rock. More than half of the Earth's crust is made of feldspar. What are igneous [...]
24
06, 2017
Hadean Eon – Earth, Moon, proteins, RNA
In the Hadean Eon, Earth was covered with active volcanoes like this one. Why is it called the Hadean Eon? Scientists named the Hadean Eon after the Greek god Hades, [...]
13
06, 2017
Middle Kingdom Egyptian Sculpture
Amenemhet III, Egyptian pharaoh By the time of the Middle Kingdom, about 2000 BC, Egyptian sculptors, like other Egyptian artists, were beginning to work in a new style. Senroset, [...]
2
06, 2017
What is tin? Atoms, elements, chemistry
Like the other metals, tin is one of the heavier kinds of atoms. Every atom of tin has 50 protons and 69 neutrons in its nucleus (depending on the isotope; the exact [...]
2
06, 2017
What is silicon? Atoms, elements, chemistry
Diagram of a silicon atom When a red giant star is getting older and runs out of helium fuel, it starts to convert the oxygen atoms in the star into silicon [...]
