Questões de Concursos Exército Brasileiro

Em algumas operações militares, grupos especiais utilizam artefatos explosivos, como granadas de mão, denominadas de Luz e Som (ou atordoantes). Após sua deflagração, a granada gera como efeitos um estampido muito alto e um intenso flash de luz, que atordoam o oponente. Algumas granadas deste tipo podem possuir como reagente componente principal o magnésio metálico em pó. Considerando a luz emitida por esta granada como resultado da reação química entre o magnésio metálico pulverizado e o oxigênio do ar, tem-se a equação da reação:

Mg (s) + O₂ (g) ? MgO (s) + luz

Acerca do magnésio e da reação descrita acima, são feitas as seguintes afirmativas:

I – Essa é uma reação de simples troca.
II – Nesta reação ocorre a oxidação do magnésio metálico.
III – Após a deflagração da granada com reação do magnésio metálico (conforme a equação da reação descrita acima), há formação de um sal de magnésio.
IV – Conforme o diagrama de Linus Pauling, a distribuição eletrônica do cátion magnésio (Mg²⁺) é: 1s², 2s², 2p⁶.
V – Após a deflagração da granada com reação do magnésio metálico (conforme a equação da reação descrita acima), ocorre a formação de óxido de magnésio e gás hidrogênio como produtos.
VI – As ligações químicas existentes entre os átomos de magnésio metálico são denominadas de metálicas e as ligações químicas existentes entre os átomos no óxido de magnésio são denominadas de iônicas.

                                    (Título omitido propositadamente)

      Italian children have been told not to turn up to school unless they can prove they have been properly vaccinated. The deadline follows months of national debate over compulsory vaccination. The new law came amid a surge in measles cases - but Italian officials say vaccination rates have improved since it was introduced. Children must receive a range of mandatory immunisations before attending school. They include vaccinations for chickenpox, polio, measles, mumps and rubella.
      Children up to the age of six years will be excluded from nursery and kindergarten without proof of vaccination under the new rules. Those aged between six and 16 cannot be banned from attending school, but their parents face fines if they do not complete the mandatory course of immunisations.
      Italian media report that regional authorities are handling the situation in a number of different ways. In Bologna, the local authority has set letters of suspension to the parents of some 300 children, and a total of 5,000 children do not have their vaccine documentation up to date. In other areas there have been no reported cases, while still others have been given a grace period of a few days beyond the deadline.
      The new law was passed to raise Italy’s dropping vaccination rates from below 80% to the World Health Organisation’s 95% target.
                                    Adapted from https://www.bbc.com/news/world-europe-47536981

                                    (Título omitido propositadamente)

      Italian children have been told not to turn up to school unless they can prove they have been properly vaccinated. The deadline follows months of national debate over compulsory vaccination. The new law came amid a surge in measles cases - but Italian officials say vaccination rates have improved since it was introduced. Children must receive a range of mandatory immunisations before attending school. They include vaccinations for chickenpox, polio, measles, mumps and rubella.
      Children up to the age of six years will be excluded from nursery and kindergarten without proof of vaccination under the new rules. Those aged between six and 16 cannot be banned from attending school, but their parents face fines if they do not complete the mandatory course of immunisations.
      Italian media report that regional authorities are handling the situation in a number of different ways. In Bologna, the local authority has set letters of suspension to the parents of some 300 children, and a total of 5,000 children do not have their vaccine documentation up to date. In other areas there have been no reported cases, while still others have been given a grace period of a few days beyond the deadline.
      The new law was passed to raise Italy’s dropping vaccination rates from below 80% to the World Health Organisation’s 95% target.
                                    Adapted from https://www.bbc.com/news/world-europe-47536981