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  • 58.062 questões
  • 160 instituições
  • 23 anos de prova

Resultados: 58.062 questões

Página 2.568 de 2.904

  • Ciências da Natureza

    Química

    DADOS QUE PODEM SER USADOS NESTA PROVA:


    ELEMENTO QUÍMICO          NÚMERO ATÔMICO       MASSA ATÔMICA

             

              H                                              1                                           1,0

             He                                             2                                           4,0

             Li                                               3                                           6,9

             C                                               6                                          12,0

             N                                               7                                          14,0

             O                                               8                                          16,0

             F                                                9                                          19,0

            Ne                                             10                                          20,2

            Na                                             11                                           23,0

            Si                                              14                                           28,1

            P                                               15                                           31,0

            S                                               16                                           32,0

           Cl                                               17                                           35,5

            K                                               19                                           39,0

           Ca                                               20                                          40,0

           Mn                                              25                                           55,0

           Co                                               27                                           58,9

           Zn                                                30                                           65,4

           Ge                                               32                                           72,6

           As                                                33                                          75,0

           Nb                                                41                                          93,0

           Pb                                                82                                          208,0 

    Com o título O Novo Ouro, a publicação Química Nova, de dezembro de 2013, trata da importância dos elementos conhecidos como terras raras. Segundo a matéria, são fundamentais para a fabricação de motores elétricos, turbinas eólicas, superímãs, telefones inteligentes, computadores, tablets, lâmpadas de LED, mísseis e muitos outros produtos. Sobre os elementos terras raras, pode-se afirmar corretamente que
    Escolha uma alternativa para a questão c66ef531-b8
  • Ciências da Natureza

    Física

    Um sistema massa-mola oscila sem atrito. A figura a seguir ilustra alguns instantâneos desse movimento durante um tempo inferior a um período de oscilação. As duas linhas tracejadas indicam os extremos do deslocamento das massas.

    Imagem da questão de Física, UECE 2014, Dinâmica

    As setas indicam a direção e o sentido do vetor velocidade da massa. Nos instantâneos 1 e 4, a mola está parcialmente comprimida; em 2 e 3, a mola está parcialmente distendida. O trabalho realizado pela força elástica em um intervalo de tempo muito pequeno e em torno de cada um dos instantâneos é t1 , t2 , t3 e t4 . Assim, é correto afirmar que
    Escolha uma alternativa para a questão c63dc2ef-b8
  • Ciências da Natureza

    Física

    Uma onda sonora vinda de uma sirene chega a um determinado ponto próximo a um ouvinte. É correto afirmar que, em decorrência dessa onda sonora, nesse ponto há
    Escolha uma alternativa para a questão c62f385c-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    While scientific research and brain gaming companies are not working with the same assumptions, Dr. Doraiswamy recommends that people
    Escolha uma alternativa para a questão c06475dc-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    Recent research undertaken with older adults at the University of California presented significant results in relation to cognitive training using a certain driving game. They are significant due to the evidence that
    Escolha uma alternativa para a questão c060efe2-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    According to Dr. Doraiswamy, from the Duke Institute for Brain Sciences, the problem about many of the cognitive training programs being offered nowadays is that
    Escolha uma alternativa para a questão c05ae75a-b8
  • Ciências da Natureza

    Biologia

    Os recifes de corais são ecossistemas de grande biodiversidade, formados principalmente por carbonato de cálcio, proveniente de esqueletos de animais e algas coralinas que se depositam nos oceanos ao longo de milhares de anos. Sobre os recifes de corais, pode-se afirmar corretamente que
    Escolha uma alternativa para a questão c0521c90-b8
  • Ciências da Natureza

    Química

    Imagem da questão de Química, UECE 2014, Equilíbrio Químico

    Em 1909, o químico dinamarquês Soren Peter Lauritz Sorensen (1868-1939) introduziu na literatura química o termo pH, que significa potencial hidrogeniônico e afere a acidez, a alcalinidade, ou a neutralidade de uma solução a uma determinada temperatura. Sabe-se, por exemplo, que o produto iônico da água neutra a 45°C é igual a 4,0 x 10-14 e log 2 = 0,30 (aproximadamente). Sobre o pH da água, assinale a afirmação FALSA.
    Escolha uma alternativa para a questão c03a6234-b8
  • Ciências da Natureza

    Física

    Um fio condutor reto é percorrido por uma corrente elétrica constante, que gera um campo magnético nas suas proximidades. Nessa situação, é correto afirmar que
    Escolha uma alternativa para a questão c0311dc8-b8
  • Ciências Humanas

    Geografia

    Desde a deflagração da crise venezuelana [...], o Brasil expressou suas posturas a respeito do tema, por meio de entidades regionais como a Unasul e o Mercosul, o bloco que integra junto com a Venezuela, a Argentina, o Paraguai e o Uruguai.
    Por que o Brasil tem sido cauteloso em relação à crise na Venezuela? http://www.bbc.co.uk/portuguese/ noticias/2014/03/140312_venezuela_cautela_lk.shtml 12/03/2014

    O Governo brasileiro se posicionou em relação a esta questão
    Escolha uma alternativa para a questão c018d538-b8
  • Ciências Humanas

    História

    Atente para o seguinte excerto a respeito da Revolução Islâmica: “O problema é que o Ocidente não entende o Irã, país persa e não árabe, e não aceita a Revolução Islâmica de 1979”.
    (Carta, G. O Irã desconhecido in: Carta Capital, São Paulo, nº 792, p.30-37, 2014.)

    Sobre a Revolução Islâmica, é correto afirmar que
    Escolha uma alternativa para a questão c006eaff-b8
  • Linguagens

    Português

    O texto 2 (subdividido em seções) faz uma reflexão sobre a maneira como se comporta, em determinado momento, a sociedade brasileira, que, mais cedo ou mais tarde, teria que integrar negros e mulatos.

    Texto 2

    Imagem da questão de Português, UECE 2014, Gêneros Textuais

    Releia o parágrafo 2 do texto 1. Você deve ter percebido que o Paulo César de que fala o texto 2 é o mesmo Paulo César de que fala Nélson Rodrigues no texto 1. Cotejando esses dois textos, marque a opção INCORRETA.
    Escolha uma alternativa para a questão bfd3a4d6-b8
  • Linguagens

    Português

    Imagem da questão de Português, UECE 2014, Figuras de Linguagem

    Sobre o trecho seguinte: “Há um tipo de vaia que explode como uma força da natureza. Sim. Uma vaia que venta, chove, troveja e relampeja” (linhas 14-16), é INCORRETO afirmar que
    Escolha uma alternativa para a questão bfc2769d-b8
  • Linguagens

    Português

    Imagem da questão de Português, UECE 2014, Interpretação de Textos

    Assinale a opção que apresenta uma voz que NÃO é a voz do enunciador.
    Escolha uma alternativa para a questão bfbd0b94-b8
  • Linguagens

    Espanhol

    Imagem da questão de Espanhol, UECE 2014, Formas Átonas | Adjetivos Posesivos
    En la concurrencia de pronombres personales átonos, es correcto decir:
    Escolha uma alternativa para a questão 6489babe-b8