Some electrical cells produce electricity without using chemical energy. For example, solar cells produce electricity when they are exposed to sun light.
A plate of zinc and a plate of copper immersed in a dilute solution which contains acid or salt is an example of the chemical reaction based cell. The solution acts as an electrolyte (electric conductor). When the two plates are connected to a current meter with a wire, electric current will pass; this is because oxidation and reduction processes take place in this chemical reaction turning the zinc plate to a negative electrode and the copper plate to a positive electrode, and so the electrons flow from zinc to copper.
Some chemical reactions need high energy to happen. An example is the breakdown of water into hydrogen and oxygen. An electrical cell (or an "electrolytic cell") is used for these reactions. It is a container which has to have a chemical reaction involving electrodes. The chemical substances are exposed to electrical power, and the electrolysis reaction happens inside the electrical cell.
Two pieces of metal are placed in water that has a little electrolyte such as hydrochloric acid, sulfuric acid, sodium bicarbonate, or sodium hydroxide added to it. An electric current is applied and gas comes out of each electrode. Some greenish-brown color may be seen too if iron was used.
There may also be a chemical reaction which will result in the explosion of the iron and has a strong blast radius (safety goggles recommended).
Dry cell
Dry cells are a type of chemical cells. Dry cells are commonly used today in the form of batteries. Dry cells are used in many electrical appliances.
Primary cells are not rechargeable. They have to be thrown away after their chemicals are used.
Secondary cells are rechargeable. They can be used again.
Vietnam War
The Vietnam War (also known as Second Indochina War or American War in Vietnam) lasted from 1 November 1955–30 April 1975, (19 years, 5 months, 4 weeks and 1 day). It was fought between North Vietnam and South Vietnam. North Vietnam was supported by the Soviet Union, China and North Korea, while South Vietnam was supported by the United States, South Korea, Thailand, Australia, New Zealand, and the Philippines. People from other countries also went to fight but not in their own national army. This conflict between communist and capitalist countries was part of the Cold War.
The Viet Cong (also known as the National Liberation Front, or NLF), was a South Vietnamese communist force helped by the North. It fought a guerrilla war against the anti-communist forces in the South. The People's Army of Vietnam (also known as the North Vietnamese Army) engaged in a more conventional war, at times putting large forces to battle.
The Vietnam War was very controversial, especially in the United States, and it was the first war to feature live television coverage. It was also the first major armed conflict that the United States lost. The war became so unpopular in the United States that President Nixon eventually agreed to send American soldiers home in 1973.
France began to colonize Vietnam between 1859 and 1862, when they took control of Saigon. By 1864 they controlled all of Cochinchina, the southern part of Vietnam. France took control of Annam, the large central part of Vietnam, in 1874. After France defeated China in the Sino-French war (1884–1885), they took over Tonkin, the northern part of Vietnam. French Indochina was formed in October 1887 from these three areas of Vietnam (Cochinchina, Annam and Tonkin), as well as the Kingdom of Cambodia. Laos was added after a war with Thailand, the Franco-Siamese War, in 1893.
During World War II, after Nazi Germany defeated the French in 1940, French Indochina was controlled by the Vichy French government, a puppet government approved by Nazi Germany. In March 1945 Imperial Japan launched the Second French Indochina Campaign. Japan occupied Indochina until their surrender in August 1945.
After the defeat of Nazi Germany, the Vichy government was no longer in control of France or its territories. The newly formed Provisional Government of the French Republic attempted to take back control of its former colonies in Indochina by force if necessary. But the French efforts at regaining their colony in Vietnam were opposed by a Vietnamese army called the Viet Minh.
The Viet Minh had been founded in 1941 by the communist party and was led by Hồ Chí Minh. This led to the First Indochina War between France and the Viet Minh. The fighting started with the French bombardment of Haiphong Harbor in November 1946 and ended with a triumph of the Viet Minh at Dien Bien Phu.
In July 1954, France and the Viet Minh signed the Geneva Peace Accord. This resulted in dividing Vietnam along the 17th parallel into a northern section, under the control of the communists led by Ho Chi Minh as president, and a southern section led by the Catholic anti-communist Ngo Dinh Diem. The partition was to be temporary until elections in 1956. However, Diem started arresting suspected communist sympathizers in 1956 to keep power for himself. The elections were never held, and in 1957 the north Vietnamese began guerrilla warfare against the south.
The United States supported the anti-communist government in South Vietnam. It began to send military advisors to help train and support the South Vietnamese army. The South was fighting against the Viet Cong, a communist party based in South Vietnam which was allied with North Vietnam. The Viet Cong began a campaign of assassination in 1957. In 1959, North Vietnam dramatically increased its military assistance to the Viet Cong, which then began attacking South Vietnamese military units. In the American domino theory they feared that if communism took hold in Vietnam, it would spread to other countries nearby.
On 2 August 1964, the destroyer USS "Maddox" was in the Gulf of Tonkin, on an intelligence mission along North Vietnam's coast. The US said that three North Vietnamese torpedo boats attacked the destroyer. The Maddox fired back and damaged the three torpedo boats. The US then claimed that two days later, the torpedo boats again attacked the "Maddox" and the destroyer USS "Turner Joy". In this second attack the US ships did not actually see the torpedo boats, but said they had found them using the ship's radar.
After the alleged second attack the U.S. launched air strikes against North Vietnam. The Congress passed the Gulf of Tonkin Joint Resolution (H.J. RES 1145) on 7 August 1964. This gave the president the power to run large-scale military operations in Southeast Asia without declaring war. There was little to no proof of these attacks and it was believed by some that they were an excuse for expanded U.S. involvement in Indochina.
The North Vietnamese and Viet Cong were supplied by a vast network of hidden trails, known as the Ho Chi Minh Trail. Which was hidden very well and many attempts were made by the U.S. to bomb and destroy it. Supplies and soldiers from North Vietnam were sent through Laos to communists forces in South Vietnam. American planes heavily bombed the Ho Chi Minh Trail; of bombs were dropped on Laos. It slowed down but did not stop the trail system.
Severe communist losses during the 1968 Tet Offensive, made it possible for the U.S. to withdraw many soldiers. As part of a policy called "Vietnamization", South Vietnamese troops were trained and equipped to replace the Americans who left. By 1973, 95 percent of the American troops were gone.
A peace treaty was signed in Paris in January 1973 by all the parties, but fighting continued until 1975.