radiocarbon dating and potassium-argon dating
Among other things, rocks have been found that are over 4 billion years old. The age of such rocks is determined by radioactive dating. Note that this is not "a" method, but perhaps 40 different methods (depending on the isotopes involved), which complement one another.The exact age of the Earth is harder to determine exactly; but basically, it must be at least as old as the oldest rocks found.
No one knows the exact number of homes destroyed by Charley in 2004, but estimated damage was $15 billion in the US.
Igneous rocks are formed when magma crystallizes and cools into a solid form. There are two types of igneous rocks--intrusive igneous rocks and extrusive igneous rocks.Intrusive:Intrusive igneous rocks are formed when the melted rock (magma) slowly rises toward, but does not reach the surface. As these pockets of magma cool slowly underground, minerals crystallize and the magma solidifies, becoming intrusive igneous rock, like granite and gabbro.Extrusive:Igneous rocks are also formed when volcanoes erupt, causing the magma to rise above the Earth's surface. When magma appears above the surface, it is called lava. Extrusive igneous rocks are formed as the lava cools above ground. Examples of extrusive igneous rock are basalt, rhyolite, pumice, and scoria.igneous rocks are formed by lavaWell When melted rock cools quickly, it hardens before any mineral crystals can grow large. as a result, igneous rocks that form above ground have small or no crystals :)Igneous Rocks are made of magma and lava because it comes out of a volcanoFrom volcanoes.from lava cooling.Molten rock cools and turns solid.
The exact shape of earth is "Oblate spheroid".
34.67589494
Lava will cool to form extrusive igneous rock. The exact type would depend on the composition of the lava.
"Igneous" is a general classification, not a specific type of rock. The hardness values vary depending on the exact composition.
As of the last estimate, there are approximately 1.01 billion boys under the age of 18 in the world. However, exact numbers can vary due to factors like population growth and data collection methods.
an approximation
an approximation
the bowlus spider (spelling probably wrong) saw it on qi
It will form extrusive igneous rock. Beyond that they exact type will vary.
The surface area of planet Saturn is 16.49 billion sq miles (42.7 billion km²).
around 9.5 billion 9,460,800,000 to be exact
There is no sampling method that will select the exact population.
No exact numbers are available. It was around 25 billion. The person who is answering 9 billion is WRONG.
Two methods: - radiocarbon dating - dendrochronology