Oxygen

OXYGEN

There is planty of it in the lithosphere and the hydrosphere, more than any other element. It can be mixed with air and it can be combined with water and with many other minerals.

· PROPERTIES: It’s a colourless, odeorless and tasteless gas and lightly water soluble. Oxygen has a great chemical activity, that’s why it can react with hearly all elements forming a lot of combinations that are in general called oxides.
It is essential for the breathing process in living things.
You can find it in two ways: normal oxygen, this one has its molecules formed with two atoms of oxygen and ozone, its molecules have three oxygen atoms.

· HOW TO OBTAIN IT: It can be obtained in laboratories in a very easy way, heating chlorine potassium.
For industry applications, big quantities of oxyegn can be obtained from air and from water.

· APPLICATIONS: Planty of oxyegn is used in autogenous welding. It’s also used in medicina, for diving, for climbing,…

THE ROOT OF THE PLANTS


The root of the plants is the part of the plant that pays attention to the ground to which it is nourished. But at the present time the botanists affirm that a difference between root and stem does not exist. We could speak of the root as of the part of the plant that absorbs substances of the ground.

The end of the root is covered by the layer or caliptra, followed of another cap with absorbent hairs that allow to the acquisition of water and mineral salts. When the plant ages, these hairs fall. The secondary roots are born of the main root.

Different types from roots, depending of their form and function exist: when they work like reserve organs, the main root sinks in the ground. Also roots with ramifications that extend in beams and aerial roots in plants exist that are not fixed in the ground... In addition we can hear other terms referred to the types by roots: fibrous, graft, napiforme, to columnar...

CALCULATION OF THE DEFORMACIÓN FORCE ONE THAT PRODUCED IN WHARF

You need this:

• Wharf


• Bracket


• A walnut


• A metal bar


• Portweights


• Weights


• Paper
  
• Tape

How to make the experience:

1. Build a rule of paper and set this rule to the metal bar of the apparatus. Thus it is vertical.


2. Hang wharf bar and then suspended portapesas at the end of the dock. Notes on the scale length and write their values.


3. Hang the wharf with different weights (25, 50, 75, 100 and 125 g) and enter what is its length reaches the wharf with each of the weights.

You can make this experience anywhere with these elements and these steps. It is a curious experience and funny.

The oil

Oil is a fossil fuel. Its colour is brown.It was formed many years ago. Organic matter made of the remains of little animals formed a deposit in the bottom and was covered by a thick layer of sediment.

The conditions to favour the formation of oil are:

-Not very much deep sea, with many nutrients.

-Sediments.

-Not much movement of water in the bottom.

The products formed by oil to appear in the three states of matter:

-Liquid: raw

-Solid: tarmac

-Gaseous: natural gas

Some adrift of oil are:

-Tarmac

-Gas

-Petrol

Bulimia and anorexia

Bulimia is a mental disorder related to food.The person who has it eats a lot of food in a short time. Then, she thinks she is fat and feels guilty. The person induces vomit and expels the food that she has ingested.
Anorexia is a similar illness, but it consists in not eating anything.These people think that their weight is very high.
These two illnesses can end up in death but many times they have cure becouse now, there are specialized clinics.

Dissolutions

Hi!

I'm going to write about dissolutions.

Dissolutions are mixtures which are formed by dissolute and solvent. Amount of dissolute has to be smaller then amout of solvent. There are two kinds of dissolutions : homogeneous dissolutions and heterogeneous dissolutions.

In homogeneous dissolutions we can't recognize their component.

We can preparate dissolutions at the laboratory when we study chemistry.

Bye!

[ Instruments to measure the temperature ]

The thermometers are a instruments that measure the temperature.

There are three types of thermometres:

●Alcohol thermometre of laboratory.

●Clinical thermometers of mercury.

●Thermometer of alcohol of environment.

To measure the temperature,there are two scales:

● The centigrade temperature scale or celsius: in this scale,the unit is a centigrade degree (ºC).

● The scientific use the Kelvin scale.In this scale,the unit is the Kelvin (K).One kelvin has got the same size that a centigrade degree,but the cero of Kelvin scale is -273ºC and yourname is absolute cero.

To transform one value of a scale to other is easy:Kelvin temperature = centigrade temperature+273