Volcanic Eruptions!!!

A volcano is generally any place on the planet where some material from the inside of the planet (magma) makes its way through to the planet's surface. When this happens, it is a volcanic eruptions. There are two types of eruptions, one is the explosive type where the volcano bursts open and lava shoots from it, the other is where the lava slowly oozes out. The volcanos erupt because the internal pressure has built up far too much and it needs to be released somehow.

Tectonic plates!!!

The Earth's surface is made up of a series of large plates and several minor plates. These plates, called tectonic plates, are always moving, generally about a few centimetres each year, which doesn’t sound that much at all really. Convection currents underneath the plates move them in different directions, this is because the ocean floors are always moving about, spreading from the centre and sinking at the edges. The edges of these plates, both minor and major, when they move against each one another, create earthquakes, volcanoes and even create mountains!

As the tectonic plates move, the world changes a little and sometimes a lot. About 200 million years ago, all the continents were one big piece of land called Pangea. Alfred Wegener, a German scientist, said that this one big piece of land slowly drifted apart, this was called continental drift. This was said in 1912 when the study of tectonic plates wasn’t around. (This theory also comes into play with the evolution of animals and humans. The ‘out of Africa’ theory for human evolution states man evolved in Africa then moved away to other parts of the world. They couldn’t do this if the world was separated as much as it is today, they didn’t have planes or ships to take them to other parts to the world. So it makes sense that the continents had to be much closer together for them to travel outside of Africa.)

http://www.moorlandschool.co.uk/earth/tectonic.htm

Three main types of boundaries exist between tectonic plates. 

The first is called a divergent boundary which occurs most often at mid-oceanic ridges. This is when two plates move away from each other, forming a break, or rift, in Earth's crust. Magma from the mantle (the middle section of the earth which is the deepest and very hot) rises up to fill the gap made from the separation of the plates, creating new crust. The results of this can be volcanic islands.

The second type is called a convergent boundary which happens when two plates move towards each other and meet. The plates that is made up of a more dense oceanic crust will often slide over the top of the plate that is made up of less dense oceanic crust. If both plates are made up of continental crust, very little subduction occurs. Instead, the plates buckle and fold to create valleys, ridges, and high mountain ranges such as the Himalayas.

The third type of boundary is called a transform boundary. At these locations, plates slide roughly alongside each other in opposite directions. The plates often get stuck as they move past each other, leading to a build-up of tension, which is ultimately released in the form of an earthquake. The more tension, the bigger the earthquake, if this occurs under water, tsunamis may occur.

http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.tectonic/

The Earth!!!

The Earth has three layer. The core (inner and outer), the mantle and the crust.

The core consists of a fluid outer core and a solid inner core (the inner core, despite being very hot, is solid because of all the pressure it is under). Because the core contains iron and nickel, when it flows it generates a magnetic field. This is the source of the Earth's magnetic field! The core is about 3500 km wide.

The mantle makes up 82% of the Earths volume and is about 2900km. The mantle, like the core, is made up of two sections, the upper and the lower mantle. The upper mantle also has two sections to it, the lithosphere which is stiffer than the asthenosphere, which is the lower part. The lower mantle is very, very strong, as it has a lot of pressure on it.

The final layer is the crust and it too has two sections. One is the continental crust and the other is the oceanic crust. The oceanic crust is the top crust and is only 7km thick, which is a lot less than the other layers of the Earth. It is mostly made up of basalt, a dark igneous rock, that is commonly found on railway lines and tram lines. The continental crust sits underneath the oceanic crust and can vary between 35-70 km in depth.

http://scign.jpl.nasa.gov/learn/plate1.htm

Right Angle Triangle and Pythagoras Theorem!!!

A right angle triangle is a triangle with, well a right angle in it. A right angle is a degree that equals to 90 degrees, while the whole triangle must equal and will always equal to 180 degrees. There is two types of right angle triangle, one being an Isosceles right angled triangle where one angle is a right angle, the other two angles are always 45° and have two equal sides. The other is a Scalene right angled triangle where one angle is a right angle and the other two are unequal angles with no sides equal either.

Pythagoras theorem is a ‘rule’ by a man named Pythagoras, who many, many years ago found an amazing fact about triangles. This fact was that ‘if the triangle had a right angle and you made a square on each of the three sides, then the biggest square had the exact same area as the other two squares put together’.

There is three sides to a triangle, a, b and c. C is always called the hypotenuse. The definition of the hypotenuse is ‘in a right angled triangle the square of the hypotenuse is equal to the sum of the squares of the other two sides’.

The formula for Pythagoras Theorem is a2 + b2 = c2 . This means the square of a (a²) plus the square of b (b²) is equal to the square of c (c²).

http://www.mathsisfun.com/pythagoras.html

http://www.mathsisfun.com/right_angle_triangle.html

Avogadro!!!

An Italian chemist named Amedeo Avogadro, who lived between, 1776 and 1856, came up with a theory that basically said there is a relationship between mole and volume, that as the mole increased, so did the volume. (nick’s lecture notes, 23/3/09)

The official theory is that ‘equal volumes of gases at the same temperature and pressure contain the same number of molecules regardless of their chemical nature and physical properties.’ (kiwi web) This all equals a number and that number, Avogadro’s number is, 6.23 x 10 to the power of 23 however some just say 6 x 10 to the 23. (as seen on my two mole videos) This can also be shown in a mathematically equation which is…

V/n = k

V = volume of the gas. 

n = amount of substance of the gas. 

k = proportionality constant

Out of this comes the ideal gas constant which is…

(p1-V1)/(T1-n1)= (p2-V2)/(T2-n2)=constant.

p = pressure of gas

T = temperate of gas

I didnt find this site to helpful, i really didnt understand what it was talking about by the end.

Kiwi web, Chemistry and NZ, 'Avogadro’s law - What is it?', viewed 29/3/09, http://www.chemistry.co.nz/avogadro.htm

Boyles Law!!!

Boyles law is th relationship between the volume and pressure. So when the pressure increases, the volume decreases. In this clip, it is shown with a simple childrens toy that makes it easy to understand!

Charles Law!!!

Charles' Law is the relationship between volume and temperature. When the temperature increases, so does the volume, this is to accommodate the gases that are moving more rapidly due to the increase of volume.