A eletrólise é um processo não espontâneo de grande importância para a indústria química. Uma de suas aplicações é a obtenção do gás cloro e do hidróxido de sódio, a partir de uma solução aquosa de cloreto de sódio. Nesse procedimento, utiliza-se uma célula eletroquímica, como ilustrado.

No processo eletrolítico ilustrado, o produto secundário obtido é o:

Texto base: Considere a fábula a seguir para responder.

Enunciado:

Escolha a frase que resume a moral do texto, estratégia comum ao final dos textos que compõem o gênero fábula.

(IFSUL) Considere um relógio com mostrador circular de raio e cujo ponteiro dos minutos tem comprimento igual ao raio do mostrador. Considere esse ponteiro como um vetor de origem no centro do relógio e direção variável. 

O módulo da soma vetorial dos três vetores determinados pela posição desse ponteiro quando o relógio marca exatamente 12 horas, 12 horas e trinta minutos e, por fim, 12 horas e 40 minutos é, em cm,  igual a

Galapagos Islands

The Galapagos Islands in the Pacific Ocean are one of the natural wonders of the world. One thousand kilometers from the South American coast, the Galapagos are home to many rare animals, such as giant tortoises, sea birds and dolphins.

The islands first became famous in 1859 when Charles Darwin, the British naturalist, who helped develop the theory of evolution, wrote about them in his book, On the Origin of Species. When Darwin visited the islands, he found there a key to ‘that great mystery of mysteries – the first appearance of new life on this earth’.

Today the islands belong to Ecuador, and 97% of the area is a national park. However, despite this protection, the park is in danger. The most serious threat comes from illegal fishing, which is slowly destroying marine life. Every day illegal nets trap and kill sharks, pelicans and dolphins.

Another threat comes from animals brought over by people who have come to live on the islands. Dogs and cats eat the sea birds, and rats and pigs eat turtle eggs. Getting these animals off the island is difficult and expensive.

Although tourism is seen as a positive thing, it also has caused problems. The population of Galapagos is growing fast with people from the mainland looking for jobs. Unfortunately the islands’ resources can’t support this growth.

Today the Galapagos is still a wonderful place, but how long will this last? ‘It’s impossible to protect the park on our own,’ says park ranger Diego Correa. ‘We need help and resources from outside and it’s up to everyone to make a contribution – the Galapagos belong to the whole world.’

Source: CAMPBELL, Colin; Rodger Sohna, Gude Kathy & Duckworth Michel

Matrix Pre-intermediate Workbook – Oxford University Press.

According to the text, the Galapagos Islands are facing three main problems nowadays: