HOW ARE MIXTURES SEPARATED?

Mixtures can be separated into their original components (because the components haven't been chemically combined). Several techniques can be used to separate mixtures: for example, filtration, distillation, evaporation or dissolution.

Filtration: This technique can be used to separate an insoluble solid from a mixture.

Picture via eschooltoday

Evaporation: This technique can be used to separate a soluble solid from a solution.

Photo via bbc.co.uk

Photo via bbc.co.uk

Photo via bbc.co.uk

Distillation: This technique can be used to separate a liquid from a solution or to separate two liquids.
 
Dissolution: This technique can be used to separate a soluble solid from an insoluble one.

WHAT'S A MIXTURE?

A mixture is a substance made up of two or more types of matter that aren't chemically combined.
There are two types of mixtures:
Homogeneous mixtures: It is a mixture that has a consistent color and texture. Every part of an homogeneous mixture has the same properties.

Homogeneous mixture Fondant au Chocolat. Photo by Ly. H via flickr

Heterogeneous mixture: It is a mixture that has a varied color or texture. Each substance in the mixture retains its specific properties.

Fruit Salad. Photo by: I, Bangin [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY 2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons

A solution is a mixture of one or more liquids, with one or more other substances. In a solution, the substances are dissolved in the liquid.
The liquid components of a solution are called solvents. The other components are called solutes.

Making a saline water solution by dissolving table salt in water. The salt is the solute and the water the solvent. Photo by Chris 73 / Wikimedia Commons [GFDL 1.3 (www.gnu.org/licenses/fdl-1.3.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

WHAT ARE THE BASIC LAWS OF REFLECTION?

Light is a form of energy that travels in waves.
Matter that is in a gaseous state is usually transparent: it doesn't reflect light.
Matter that is liquid usually has a smooth reflective surface.
Solid matter usually has a rougher surface than liquid, so it reflects light but they don't produce a reflection.
REFLECTION AND DIFFUSION:
When light hits a smooth surface, it's reflected regularly.

Image from https://www.orcagrowfilm.com/Articles.asp?ID=148

When light hits a rough surface, it's reflected irregularly. This is called diffusion.

Image from https://www.orcagrowfilm.com/Articles.asp?ID=148

ELECTRICITY:
All matter is made up of atoms. Each atom consists of protons, neutrons and one or more electrons.

By The original uploader was Fastfission at English Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html), GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

 The protons (positive charge +) and neutrons (neutral: no charge) make up the nucleus. The electrons (negative charge -) rotate around the nucleus in orbits. Electricity is a form of energy that's created when electrons move from the orbit of one nucleus to that of another.
When atoms lose electrons, matter becomes positively charged.
When atoms gain electrons, matter becomes negatively charged.

HOW HAVE ART AND CULTURE DEVELOPED IN SPAIN IN THE 20TH CENTURY?

Spain has produced some of the most famous artists of this period.
Cubism and Surrealism were artistic movements that developed in the first half of the 20th century.
Cubism used geometric shapes to represent people and things.
Pablo Picasso was one of the inventors of Cubism. His painting Guernica is a good example.

Picasso. By Revista Vea y Lea (cuadrado por Juan Pablo Arancibia Medina) [Public domain], via Wikimedia Commons

Guernica. Photo by jmussuto, via Bethany Lutheran College.

Surrealism represented imaginary scenes and fantasies. Salvador Dalí (The persistence of memory)

Salvador Dalí. By Roger Higgins, World Telegram staff photographer [Public domain], via Wikimedia Commons

The persistence of memory. Via Wikipedia

 and Joan Miró (Harlequin's carnival)

Joan Miró (1935). Photo by Carl Van Vechten [Public domain], via Wikimedia Commons

The Harlequin's Carnival. Photo from Wikipedia.

were important Surrealist artists.
Abstract art developed in the second half of the 20th century. It represented ideas rather than reality.
Eduardo Chillida was an important abstract sculptor (Eulogy to the Horizon).

Eduardo Chillida. Photo from Wikipedia.

By Roberto Sueiras Revuelta. (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons

The Generation of '27 was a group of poets who experimented with new styles of poetry and artistic expression.

The Generation of '27. Photo from https://kbenglishhlg.wikispaces.com/Generation+27

The group included Miguel Hernandez and Federico García Lorca. The Civil War split the group: García Lorca was killed by the Nationalists and Miguel Hernández died in prison.

Federico García Lorca. See page for author [Public domain], via Wikimedia Commons

Miguel Hernández. See page for author [Public domain], via Wikimedia Commons

WHAT HAS HAPPENED IN SPAIN SINCE 1975?

Today, Spain is a democracy. Every four years there are elections to choose the government.
After Juan Carlos became king in 1975, the transition to democracy began. It ended in 1978 with a new constitution. Important reforms were introduced by the prime minister, Adolfo Suarez.

By Verhoeff, Bert / Anefo (Nationaal Archief) [CC BY-SA 3.0 nl (http://creativecommons.org/licenses/by-sa/3.0/nl/deed.en)], via Wikimedia Commons

• All political parties were made legal.
• there was a democratic election in 1977.
• A new costitution was written.

By Infinauta (Own work) [Public domain], via Wikimedia Commons

 In 1978 people voted in favor of the constitution in a referendum. It established that:
Citizens have rights and responsibilities. Everyone must obey the law.
Citizens vote for their representatives freely in elections.
Spain recognises regional autonomy.
Spain is a parliamentary monarchy. The monarch is head of state but doesn´t govern or make laws.
Government is separated into three branches: the legislative, executive and judicial branches.

Since the transition two parties have governed Spain most of the time: the Socialist party (PSOE) and the Popular party (PP).
In 1981 there was an attemp military coup against the government led by Tejero. It failled.

Tejero. Photo by Manuel Pérez Barriopedro

In 1986 Spain became a member of the EEC (now UE).

By MPD01605 [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

In 1992 the euro replaced the peseta as Spain´s currency.

By Iu96 (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

By Avij (talk · contribs) (Own work) [ECB decisions ECB/2003/4 and ECB/2003/5 or Public domain], via Wikimedia Commons</a>

WHAT WAS SPAIN LIKE DURING FRANCO'S DICTATORSHIP?

After the Nationalists won the Spanish Civil War, Franco established his dictatorship. He took complete control of the country.
This dictatorship was based on three pillars: the military, the Catholic Church and the Falange.

• The constitution was abolished and there were no more democratic elections.
• Political parties became illegal.
• Trade unions becme illegal.
• Freedom of press was controlled by censorship.
• There was no regional autonomy.

Many people who opposed Franco went to live in the United Kingdom, France and other countries. Republicans who stayed in Spain were often imprisoned or killed.
In the 1940s and 1950s: there wasn't much food and most people were very poor. Spain didn't participate in the Second World War but Franco supported Germany. Spain wasn't allowed to be a member of the United Nations because it was a dictatorship.

In the 1960s: the economy started to improve. Tourism started to become important. Franco named Juan carlos de Borbón as his sucessor.
In the 1970s: Franco was ill and old. His supporters were divided: some wanted to continue as before and others wanted reform. Admiral Carrero Blanco was prime minister. He wanted to continue the dictatorship without any reforms. He was killed by the Basque terrorist group ETA in 1973. In 1975 Franco died and Juan Carlos became King of Spain.

WHAT WAS THE SPANISH CIVIL WAR?

In July 1936 a military rebellion began in Spanish Morocco. Its leader was General Francisco Franco.

Francisco Franco. Via Wikimedia Commons

The rebels took control of parts of Spain. The country became divided between areas controlled by the Nationalists (the rebels led by Franco) and areas controlled by the Second Republic.

Spanish Civil War August-September 1936. Booshank at en.wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], from Wikimedia Commons

Franco and the Nationalists were opposed to the changes of the Secon Republic. They wanted to replace the republic with a right-wing dictatorship (Germany and Italy supported them). The Republicans supported the Second Republic (Russia, the Soviet Union, supported them).
For three years there was fighting, until the Nationalists took control of Madrid. The war ended in April 1939. The Nationalists won, the Second Republic ended and Franco established a right-wing dictatorship.

Consequences from the war:

• 365.000 people died.
• Many people lost their family.
• People were imprisoned or killed because of their opinions (Nationalists who lived in the Republican zones and Republicans who lived in the Nationalists zones).
• Roads, bridges, railways and buildings were destroyed.
• People became ill because there wasn't enough food.

WHAT HAPPENED IN SPAIN IN THE EARLY TWENTIETH CENTURY?

The start of the 20th century was the continuation of the Restoration, which began when Alfonso XII became king in 1874. Alfonso XII died in 1885.

Alfonso XII and his second wife María Cristina. By F. Barcia Viet. Sevilla (Los Borbones) [Public domain], via Wikimedia Commons

 Spain was ruled by his wife María Cristina until Alfonso XIII turned 16 in 1902.

Alfonso XIII. By Christian Franzen [Public domain], via Wikimedia Commons.

 During Alfonso XIII's reign Spain experienced political and social conflict.

• The Liberals and Conservatives continued to take turns in government. Republican parties, the Socialist party and nationalist parties in Cataluña and Pais Vasco opposed them.
• There were many strikes, workers demanded better working conditions.
• Spain was involved in military conflict in its new colonies in Morocco.

In 1923 there was a military coup. General Primo de Rivera established a dictatorship with Alfonso XIII's support:

• The constitution was suspended, the king lost most of his powers.
• Political parties became illegal.
• Freedom of press was limited by censorship.

Alfonso XII y Miguel Primo de Rivera. Bundesarchiv, Bild 102-09411 / Unknown / CC-BY-SA 3.0 [CC BY-SA 3.0 de (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en)], via Wikimedia Commons

At first Primo de Rivera was supported by many people. Later on he had the opposition from the army and from Alfonso XIII. Primo de Rivera resigned in 1930.

 In 1931 the Republicans and the Socialists won the municipal elections and the Second Republic began. Manuel Azaña became president.

Manuel Azaña. See page for author [Public domain], via Wikimedia Commons

There was a new constitution and Spain became a democracy: all men and women could vote. There were many other changes:

• The church lost control of education. Public schools were established.
• There was more regional autonomy. There was a statute of autonomy for Cataluña. 
• The Industrial Revolution changed how society was organised.

These reforms divided Spanish society and caused political conflict.: Left-wing people supported the changes,  Right-wing people opposed the changes.

MEDICAL ADVANCES HELP REPRODUCTION

Medical advances can help at specific stages of reproduction.
Fertilisation: In-vitro fertilisation is a procedure that involves joining the male and female reproductive cells outside the woman's body, in a laboratory. If fertilisation occurs, the zygote is placed inside the woman's uterus.

Birth: one of the problems which can occur during birth is the breech birth, doctors usually perform a Cesarean section. They extract the fetus through a small cut they open through the lower abdomen and the wall of the uterus, instead of through the mother's vagina.

Click on this photo to watch a video about Cesarean Section.

Pregnancy: during pregnancy specialist doctors check the mother and the fetus health. They analyse blood and urine samples to detect infections in the fetus. To detect problems (abnormalities) in the fetus, doctors analyse amniotic fluid extracted from the amniotic sac. This procedure is known as amniocentesis. They also use an ultrasound scan to check the developing organs and bones in the fetus and its growth as well.

FERTILISATION

FERTILISATION

A man and a woman have sexual intercourse. The man deposits his semen in the woman's vagina. The sperm cells swim into the uterus and up the fallopian tubes, where one of them will fertilise the female egg cell. When a sperm cell joins with an egg cell in the fallopian tube, they form a new cell called a zygote (click here to watch a video about fertilisation). The zygote that results goes into the uterus. as it travels, it divides many times to form a group of cells called an embryo, and finally it develops into a fetus.

Zygote at the eight cell stage. Via bbc.co.uk

8 cell embryo at day 3. By ekem, Courtesy: RWJMS IVF Program [Public domain], via Wikimedia Commons.

Fetus 3 months. By National Museum of Health and Medicine [Public domain], via Wikimedia Commons.

PREGNANCY

Pregnancy is the period of time between the fertilisation of an egg cell and the birth of a baby.

The placenta provides the fetus with oxygen and nutrients from the mother's blood. It also takes away carbon dioxide and waste that the fetus produces.

The fetus is connected to the placenta by the umbilical cord.

The amniotic sac contains a liquid called amniotic fluid. This liquid supports the fetus and protects it.

Placenta and umbilical cord. By Gray38.png: User Magnus Manske on en.wikipedia derivative work: Amada44  talk to me (Gray38.png) [Public domain, Public domain, Public domain or Public domain], via Wikimedia Commons

Fetus in the amniotic sac, via howitworksdaily.com

WHAT HAPPENS DURING BIRTH?

During birth (click on the word birth to watch a video) the walls of the uterus start to contract. Then the cervix gets wider to enable baby to come out of the uterus. Next the amniotic sac breaks and the contractions push the baby into the vaginal canal.

Once the baby is outside the mother's body he starts to breathe and the doctor cuts the umbilical cord. Finally the amniotic sac, the placenta and the rest of the umbilical cord are expelled. 

THE MENSTRUAL CYCLE

During puberty a girl's ovaries start to release eggs. every 28 days a mature egg cell is released from one of the ovaries, it travels down a fallopian tube to the uterus. It stays here for some days waiting to be fertilised. If the egg is not fertilised it leaves the body with blood and tissue. This is called the menstrual cycle.

THE FEMALE REPRODUCTIVE SYSTEM

The female reproductive system is formed by external sex organs and internal sex organs (located inside the pelvis).
The ovaries produce egg cells. There is one ovary on each side of the uterus.
The uterus is where a fertilised egg cell develops into a fetus.
The fallopian tubes connect the ovary with the uterus. The egg cell travels along them.
The cervix is the narrow part of the uterus that leads to the vagina.
The vagina is a muscular canal that leads from the vulva (the external organ) to the uterus.

Female Reproductive System, by CDC, Mysid [Public domain], via Wikimedia Commons

Female Reproductive System, via pixgood.com.

WHAT ARE REPRODUCTIVE CELLS LIKE?

There are two types of human reproductive cells which are called gametes: the female egg cell (ovum) and the male sperm cell (spermatozoon). A female egg is round and much larger than a sperm cell. A sperm cell has a small head and a long tail which helps it to move around.

Egg cell, Henry Vandyke Carter
[Public domain], via Wikimedia Commons

Sperm cells, By Bobjgalindo (Own work)
[GFDL (http://www.gnu.org/copyleft/fdl.html)
or CC BY-SA 4.0-3.0-2.5-2.0-1.0
(http://creativecommons.org/licenses/by-sa/4.0-3.0-2.5-2.0-1.0)],
via Wikimedia Commons

Sperm cell and egg cell fusing, via Wikipedia.

Reproduction can be sexual or asexual.
In sexual reproduction the male and the female gametes combine to produce a fetus and contains DNA from each one.

SEX CHARACTERISTICS

The differences between male and female bodies are called sex characteristics.
Primary sex characteristics are the differences between the male and the female reproductive organs.
Secondary sex characteristics aren't directly related to reproduction (facial hair...).