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Resultados: 58.062 questões

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  • Ciências da Natureza

    Química

    Existem substâncias corriqueiramente utilizadas como antiácido no nosso dia a dia. Uma determinada substância com essa ação apresenta na sua composição, em massa, 27,38% de sódio, 1,19% de hidrogênio, 14,28% de carbono e 57,14% de oxigênio. Indique a alternativa com a fórmula do composto.

    Dados: massa atômica H=1, C=12, O=16, Na=23
    Escolha uma alternativa para a questão 67f3e60c-b3
  • Ciências da Natureza

    Química

    O maior diamante do mundo foi encontrado em 1905 na Mina Premier, na África do Sul. A peça possuía uma massa de aproximadamente 600 gramas. Considerando que o grafite e o diamante são formas alotrópicas do carbono, assinale a alternativa que apresenta o calor necessário para a obtenção de um diamante sintético com massa de 600 gramas a partir de grafite.

    Dados:

    Massa atômica: C = 12 O = 16
    Cgrafite + O2(g) → CO2(g) ΔH= - 393,5 kJ/mol
    Cdiamante + O2(g) → CO2(g) ΔH= - 395,4 kJ/mol
    Escolha uma alternativa para a questão 67eef43f-b3
  • Ciências da Natureza

    Química

    O piracetam é uma droga que manipula os neurotransmissores cerebrais e acredita-se que apresenta efeitos positivos sobre a inteligência. Alguns países comercializam o produto como suplemento alimentar, apesar de sua ação ainda não ser totalmente compreendida. Entretanto, em países como o Brasil, a droga não pode ser comprada sem prescrição médica.

    Imagem da questão de Química, IF Sul - MG 2017, Principais Funções Orgânicas: Funções Nitrogenadas: Amina, Amida, Nitrila, Isonitrila e Nitro Composto.

    Na estrutura da molécula do piracetam representada é possível identificar as seguintes funções orgânicas:
    Escolha uma alternativa para a questão 67ebcddc-b3
  • Ciências da Natureza

    Química

    Um estudante deseja guardar uma solução aquosa 1 mol/L de CoCl2 em um recipiente a 25 ºC. Para isso, no laboratório de química há disponível recipientes dos seguintes materiais:

    I. Alumínio
    II. Ferro
    III. Níquel
    IV. Cobre
    V. Prata

    Assinale a alternativa que apresenta somente materiais em que a solução pode ser armazenada sem ocorrência de reação com o recipiente:

    Dados:

    Al3+(aq) + 2e- → Al(s)      E°=-1,66 V
    Fe2+(aq) + 2e- → Fe(s)   E°=-0,44 V
    Ni2+(aq) + 2e- → Ni(s)    E°=-0,25 V
    Co2+(aq) + 2e- → Co(s)  E°=-0,28 V
    Cu2+(aq) + 2e- → Cu(s)  E°=+0,34 V
    Ag+(aq) + 2e- → Ag(s)    E°=+0,80 V
    Escolha uma alternativa para a questão 67e8eedc-b3
  • Ciências da Natureza

    Biologia

    No Felis catus (gato doméstico) os alelos A e a ligados ao cromossomo X auxiliam na determinação da cor de sua pelagem. O alelo dominante A determina a pelagem laranja e é epistático sobre os alelos autossômicos M e m. O alelo recessivo a não determina pelo laranja e possibilita a manifestação dos alelos autossômicos responsáveis pela cor preta (MM ou Mm) ou marrom (mm). Uma gata alaranjada e heterozigota para o par autossômico, filha de um macho (pai) alaranjado e de uma fêmea (mãe) alaranjada e homozigota para os alelos sexuais, foi cruzada com um gato preto e heterozigoto para o gene autossômico. Qual será a proporção fenotípica esperada para os descendentes?
    Escolha uma alternativa para a questão 67e4f475-b3
  • Ciências da Natureza

    Biologia

    De acordo com o Prof. M. Marangon, em “Estabilidade de taludes”.

    Disponível em:<http://www.ufjf.br/nugeo/files/2009/11/togot_Unid04EstabilidadeTaludes01.pdf>. A. Acesso em: 03 set.2017.

    “Nos projetos de estabilização dos taludes é fundamental atuar sobre os mecanismos instabilizadores. Assim, sufocando a causa com obras ou soluções de alto efeito ... os efeitos da erosão podem ser combatidos com a proteção vegetal...”

    Algumas plantas, por suas características morfológicas, são mais apropriadas para conter a erosão do solo em taludes, encostas de morros e beiras de estradas. Entre tais plantas costuma-se usar principalmente espécies de angiospermas monocotiledôneas, do grupo das gramíneas, atualmente família Poaceae. As características abaixo normalmente são presentes numa monocotiledônea, exceto:
    Escolha uma alternativa para a questão 67e11967-b3
  • Ciências da Natureza

    Biologia

    Organismos transgênicos receberam genes de outras espécies de seres vivos, com características desejadas, em função de produzirem substâncias de interesse do próprio homem. Além do DNA cromossômico, bactérias possuem plasmídeos e algumas enzimas especiais capazes de fragmentar naturalmente (cortar) pedaços de DNA. Qual alternativa indica corretamente o que é um plasmídeo e o nome dessas enzimas, respectivamente?
    Escolha uma alternativa para a questão 67dcf3d5-b3
  • Ciências da Natureza

    Biologia

    O núcleo eucariótico contém nucleoplasma, nucléolo e cromatina delimitados pela carioteca. A cromatina é associada a proteínas e constitui parte do material genético das células. O núcleo é responsável pelo metabolismo e pela divisão da célula. O ciclo celular é o conjunto de processos que ocorre numa célula viva entre duas divisões celulares. Ele consiste na interfase e na mitose. A mitose propriamente dita compreende a divisão do núcleo e a citocinese – divisão do citoplasma. Quanto aos componentes do núcleo e dos processos de divisão mitótica e meiótica e aspectos deles decorrentes, assinale a alternativa correta.
    Escolha uma alternativa para a questão 67d8de75-b3
  • Ciências da Natureza

    Biologia

    Qualquer que seja o tipo celular, as células são formadas por substâncias inorgânicas e orgânicas essenciais aos processos metabólicos que nelas ocorrem. Quanto a tais substâncias assinale a alternativa incorreta.
    Escolha uma alternativa para a questão 67d456ef-b3
  • Matemática

    Matemática

    Um reservatório de água tem o formato de um prisma hexagonal regular, cujo lado mede 4 m e tem profundidade igual a 5 m. A capacidade desse reservatório é igual a:
    Escolha uma alternativa para a questão 67cd33d7-b3
  • Linguagens

    Inglês

    • Leia o texto e responda às questões:
    How has Princess Diana's death changed the Royal Family?
    The death of Princess Diana in 1997, and the public's response to it, shook the House of Windsor.

    Twenty years on, there's been a coup at the palace. It was bloodless. All the royals remain standing. But the power has shifted.
    The departure, earlier this month, of the Queen's dedicated senior official Sir Christopher Geidt has meant her eldest son can exert more control over the monarchy's direction of travel.
    The comings and goings of courtiers excite those on the inside and leave outsiders cold.
    However, recent changes should cheer Prince Charles. The heir who's waited and waited is more content and less anguished.
    He's still driven by a desire to deliver change but the royal prophet in the wilderness on climate change has been embraced by the mainstream.
    A prince once derided for talking to plants is praised for trying to save the planet.
    With each year that passes, his mother will do less and he will do more.
    There are fewer clouds on his horizon. It's a horizon that was once obscured by the War of the Waleses:
    his televised admission of adultery, and his leaked comments about tampons.

    Lasting influence

    And yet, and yet. Whatever accommodation he reached with his first wife in life hasn't survived her death. Diana haunts Charles.
    A recent YouGov poll commissioned by the Press Association suggested that the number of people who believe the Prince of Wales has made a positive contribution to the Royal Family has fallen over the past four years, down from 60% to 36%.
    This polling took place at a time when it was hard to escape references to Charles's painful past.
    Newspapers and television channels have reflected at length on the influence of Diana, Princess of Wales, an influence that stretched from fashion to the British monarchy.
    It's been a month of coverage that must have perplexed anyone under the age of 25 and would have confused a visiting Martian.
    Charles's many supporters will argue that Diana's adverse impact on his popularity will recede with each passing year. But 20 years on, her influence still registers.(...)

    Disponível em: <http://www.bbc.com/news/uk-41094816/. Acesso em: Agosto de 2017)


    Observe a seguinte frase:

    “And yet and yet. Whatever accommodation he reached with his first wife in life hasn't survived her death. Diana haunts Charles”.

    Uma tradução para o termo grifado “Whatever” no context da frase seria:
    Escolha uma alternativa para a questão 67a6a56a-b3
  • Linguagens

    Inglês

    • Leia o texto e responda às questões:
    How has Princess Diana's death changed the Royal Family?
    The death of Princess Diana in 1997, and the public's response to it, shook the House of Windsor.

    Twenty years on, there's been a coup at the palace. It was bloodless. All the royals remain standing. But the power has shifted.
    The departure, earlier this month, of the Queen's dedicated senior official Sir Christopher Geidt has meant her eldest son can exert more control over the monarchy's direction of travel.
    The comings and goings of courtiers excite those on the inside and leave outsiders cold.
    However, recent changes should cheer Prince Charles. The heir who's waited and waited is more content and less anguished.
    He's still driven by a desire to deliver change but the royal prophet in the wilderness on climate change has been embraced by the mainstream.
    A prince once derided for talking to plants is praised for trying to save the planet.
    With each year that passes, his mother will do less and he will do more.
    There are fewer clouds on his horizon. It's a horizon that was once obscured by the War of the Waleses:
    his televised admission of adultery, and his leaked comments about tampons.

    Lasting influence

    And yet, and yet. Whatever accommodation he reached with his first wife in life hasn't survived her death. Diana haunts Charles.
    A recent YouGov poll commissioned by the Press Association suggested that the number of people who believe the Prince of Wales has made a positive contribution to the Royal Family has fallen over the past four years, down from 60% to 36%.
    This polling took place at a time when it was hard to escape references to Charles's painful past.
    Newspapers and television channels have reflected at length on the influence of Diana, Princess of Wales, an influence that stretched from fashion to the British monarchy.
    It's been a month of coverage that must have perplexed anyone under the age of 25 and would have confused a visiting Martian.
    Charles's many supporters will argue that Diana's adverse impact on his popularity will recede with each passing year. But 20 years on, her influence still registers.(...)

    Disponível em: <http://www.bbc.com/news/uk-41094816/. Acesso em: Agosto de 2017)


    O tempo verbal grifado na seguinte frase “Twenty years on, there's been a coup at the palace” é o:
    Escolha uma alternativa para a questão 67a3b472-b3
  • Linguagens

    Inglês

    • Leia o texto e responda às questões:
    How has Princess Diana's death changed the Royal Family?
    The death of Princess Diana in 1997, and the public's response to it, shook the House of Windsor.

    Twenty years on, there's been a coup at the palace. It was bloodless. All the royals remain standing. But the power has shifted.
    The departure, earlier this month, of the Queen's dedicated senior official Sir Christopher Geidt has meant her eldest son can exert more control over the monarchy's direction of travel.
    The comings and goings of courtiers excite those on the inside and leave outsiders cold.
    However, recent changes should cheer Prince Charles. The heir who's waited and waited is more content and less anguished.
    He's still driven by a desire to deliver change but the royal prophet in the wilderness on climate change has been embraced by the mainstream.
    A prince once derided for talking to plants is praised for trying to save the planet.
    With each year that passes, his mother will do less and he will do more.
    There are fewer clouds on his horizon. It's a horizon that was once obscured by the War of the Waleses:
    his televised admission of adultery, and his leaked comments about tampons.

    Lasting influence

    And yet, and yet. Whatever accommodation he reached with his first wife in life hasn't survived her death. Diana haunts Charles.
    A recent YouGov poll commissioned by the Press Association suggested that the number of people who believe the Prince of Wales has made a positive contribution to the Royal Family has fallen over the past four years, down from 60% to 36%.
    This polling took place at a time when it was hard to escape references to Charles's painful past.
    Newspapers and television channels have reflected at length on the influence of Diana, Princess of Wales, an influence that stretched from fashion to the British monarchy.
    It's been a month of coverage that must have perplexed anyone under the age of 25 and would have confused a visiting Martian.
    Charles's many supporters will argue that Diana's adverse impact on his popularity will recede with each passing year. But 20 years on, her influence still registers.(...)

    Disponível em: <http://www.bbc.com/news/uk-41094816/. Acesso em: Agosto de 2017)


    Observe a frase retirada do texto e escolha a opção CORRETA:


    “It’s a horizon that was once obscured by the War of the Waleses”

    Escolha uma alternativa para a questão 679f9433-b3
  • Linguagens

    Inglês

    • Leia o texto e responda às questões:
    How has Princess Diana's death changed the Royal Family?
    The death of Princess Diana in 1997, and the public's response to it, shook the House of Windsor.

    Twenty years on, there's been a coup at the palace. It was bloodless. All the royals remain standing. But the power has shifted.
    The departure, earlier this month, of the Queen's dedicated senior official Sir Christopher Geidt has meant her eldest son can exert more control over the monarchy's direction of travel.
    The comings and goings of courtiers excite those on the inside and leave outsiders cold.
    However, recent changes should cheer Prince Charles. The heir who's waited and waited is more content and less anguished.
    He's still driven by a desire to deliver change but the royal prophet in the wilderness on climate change has been embraced by the mainstream.
    A prince once derided for talking to plants is praised for trying to save the planet.
    With each year that passes, his mother will do less and he will do more.
    There are fewer clouds on his horizon. It's a horizon that was once obscured by the War of the Waleses:
    his televised admission of adultery, and his leaked comments about tampons.

    Lasting influence

    And yet, and yet. Whatever accommodation he reached with his first wife in life hasn't survived her death. Diana haunts Charles.
    A recent YouGov poll commissioned by the Press Association suggested that the number of people who believe the Prince of Wales has made a positive contribution to the Royal Family has fallen over the past four years, down from 60% to 36%.
    This polling took place at a time when it was hard to escape references to Charles's painful past.
    Newspapers and television channels have reflected at length on the influence of Diana, Princess of Wales, an influence that stretched from fashion to the British monarchy.
    It's been a month of coverage that must have perplexed anyone under the age of 25 and would have confused a visiting Martian.
    Charles's many supporters will argue that Diana's adverse impact on his popularity will recede with each passing year. But 20 years on, her influence still registers.(...)

    Disponível em: <http://www.bbc.com/news/uk-41094816/. Acesso em: Agosto de 2017)


    Escolha a alternativa FALSA sobre o texto:
    Escolha uma alternativa para a questão 679aeb2a-b3