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QUESTION 1 You have a hybrid Exchange Server 2016 organization. Some of the mailboxes in the research department are hosted on-premises. Other mailboxes in the research department are stored in Microsoft Office 365. You need to search the mailboxes in the research department for email messages that contain a specific keyword in the message body. What should you do? A. From the Exchange Online Exchange admin center, search the delivery reports. B. Form the on-premises Exchange center, search the delivery reports. C. From the Exchange Online Exchange admin SY0-401 exam center, create a new In-Place eDiscovery & Hold. D. From the Office 365 Compliance Center, create a new Compliance Search. E. From the on-premises Exchange admin center, create a new In-Place eDiscovery & Hold. Correct Answer: E QUESTION 2 You have an Exchange Server 2016 organization. You plan to enable Federated Sharing. You need to create a DNS record to store the Application Identifier (AppID) of the domain for the federated trust. Which type of record should you create? A. A B. CNAME C. SRV D. TXT Correct Answer: D QUESTION 3 Your company has an Exchange Server 2016 200-310 exam Organization. The organization has a four- node database availability group (DAG) that spans two data centers. Each data center is configured as a separate Active Directory site. The data centers connect to each other by using a high-speed WAN link. Each data center connects directly to the Internet and has a scoped Send connector configured. The company's public DNS zone contains one MX record. You need to ensure that if an Internet link becomes unavailable in one data center, email messages destined to external recipients can 400-101 exam be routed through the other data center. What should you do? A. Create an MX record in the internal DNS zone B. B. Clear the Scoped Send Connector check box C. Create a Receive connector in each data center. D. Clear the Proxy through Client Access server check box Correct Answer: AQUESTION 4 Your network contains a single Active Directory forest. The forest contains two sites named Site1 and Site2. You have an Exchange Server 2016 organization. The organization contains two servers in each site. You have a database availability group (DAG) that spans both sites. The file share witness is in Site1. If a power failure occurs at Site1, you plan to mount the databases in Site2. When the power is restored in Site1, you Cisco CCNP Security 300-207 exam SITCS need to prevent the databases from mounting in Site1. What should you do? A. Disable AutoReseed for the DAG. B. Implement an alternate file share witness. C. Configure Datacenter Activation Coordination (DAC) mode. D. Force a rediscovery of the EX200 exam network when the power is restored. Correct Answer: C QUESTION 5 A new company has the following: Two offices that connect to each other by using a low-latency WAN link In each office, a data center that is configured as a separate subnet Five hundred users in each office You plan to deploy Exchange Server 2016 to the network. You need to recommend which Active Directory deployment to use to support the Exchange Server 2016 deployment What is the best recommendation to achieve the goal? A. Deploy two forests that each contains one site and one site link. Deploy two domain controllers to each forest. In each forest configure one domain controller as a global catalog server B. Deploy one forest that contains one site and one site link. Deploy four domain controllers. Configure all of the domain controllers as global catalog servers. C. Deploy one forest that contains two sites and two site links. Deploy two domain controllers to each site in each site, configure one domain controller as a global catalog server D. Deploy one forest that contains two sites and one site link. Deploy two domain controllers to each site. Configure both domain controllers as global catalog servers Correct Answer: C QUESTION 6 How is the IBM Content Template Catalog delivered for installation? A. as an EXE file B. as a ZIP file of XML files C. as a Web Appli cati on Archive file D. as a Portal Application Archive file Correct Answer: D QUESTION 7 Your company has a data center. The data center contains a server that has Exchange Server 2016 and the Mailbox server role installed. Outlook 300-101 exam anywhere clients connect to the Mailbox server by using thename outlook.contoso.com. The company plans to open a second data center and to provision a database availability group (DAG) that spans both data centers. You need to ensure that Outlook Anywhere clients can connect if one of the data centers becomes unavailable. What should you add to DNS? A. one A record B. two TXT records C. two SRV records D. one MX record Correct Answer: A QUESTION 8 You have an Exchange Server 2016 EX300 exam organization. The organization contains a database availability group (DAG). You need to identify the number of transaction logs that are in replay queue. Which cmdlet should you use? A. Test-ServiceHealth B. Test-ReplicationHealth C. Get-DatabaseAvailabilityGroup D. Get-MailboxDatabaseCopyStatus Correct Answer: D QUESTION 9 All users access their email by using Microsoft Outlook 2013 From Performance Monitor, you discover that the MSExchange Database\I/O Database Reads Average Latency counter displays values that are higher than normal You need to identify the impact of the high counter values on user connections in the Exchange Server organization. What are two client connections 400-051 exam that will meet performance? A. Outlook on the web B. IMAP4 clients C. mobile devices using Exchange ActiveSync D. Outlook in Cached Exchange ModeE. Outlook in Online Mode Correct Answer: CE QUESTION 10 You work for a company named Litware, Inc. that hosts all email in Exchange Online. A user named User1 sends an email message to an Pass CISCO 300-115 exam - test questions external user User 1 discovers that the email message is delayed for two hours before being delivered. The external user sends you the message header of the delayed message You need to identify which host in the message path is responsible for the delivery delay. What should you do? A. Review the contents of the protocol logs. B. Search the message tracking logs. C. Search the delivery reports 200-355 exam for the message D. Review the contents of the application log E. Input the message header to the Exchange Remote Connectivity Analyzer Correct Answer: E QUESTION 11 You have an Exchange Server 2016 organization. The organization contains three Mailbox servers. The servers are configured as shown in the following table You have distribution group named Group1. Group1 contains three members. The members are configured as shown in the following table. You discover that when User1 sends email messages to Group1, all of the messages are delivered to EX02 first. You need to identify why the email messages sent to Group1 are sent to EX02 instead. What should you identify? A. EX02 is configured as an expansion server. B. The arbitration mailbox is hosted 300-320 exam on EX02.C. Site2 has universal group membership caching enabled. D. Site2 is configured as a hub site. Correct Answer: A
Home / Química / Boro

Boro

História

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Durante séculos a única fonte de bórax, Na2B2O5(OH)4, foi os depósitos cristalizados de Lake Yamdok Cho, no Tibete.

Foi utilizado como um fundente utilizado por ourivesaria.

Em 1808, Louis-Josef Gay-Lussac e Louis-Jacques Thénard trabalhando em Paris, e Sir Humphry Davy em Londres, extraídos independentemente do boro por aquecimento de bórax com metal de potássio.

De fato, nem havia produzido o elemento puro que é quase impossível de obter.

Um tipo mais puro de boro foi isolado em 1892 por Henri Moissan.

Eventualmente, E. Weintraub nos EUA produziu boro totalmente puro por provocando uma mistura de cloreto de boro, BCl3 vapor e hidrogênio.

O assim obtido material de boro foi encontrada para ter propriedades muito diferentes para os anteriormente relatados.

Boro puro é um pó amorfo escuro.

Símbolo – B

Elemento do grupo III, constituinte do bloco p da Tabela Periódica.

Número atômico: 5,
Configuração eletrônica:
1s22s22p1,
MA =
10,81,
d =
2,35 g.cm-3,
PF =
2079°C,
PE =
2550°C.
Número de prótons / Elétrons:
5
Número de nêutrons: 6
Densidade @ 293 K: 2,34 g / cm3
Cor: marrom
Data da descoberta:
1808
Descobridor: Sir Humphry Davy, JL Gay-Lussac
Nome de Origem: A partir de bórax e de carbono
Usos: ligas resistentes ao calor
Obtido a partir de: kernite

Apresenta duas formas alotrópicas: boro amorfo que é um pó marrom e boro metálico que é preto.

A forma metálica é muito dura (9,3 na escala de Mohs) e é mau condutor elétrico à temperatura ambiente.

Pelo menos três fases cristalinas são possíveis: duas romboédricas e uma tetragonal.

O elemento nunca foi encontrado livre na natureza.

Ocorre como ácido ortobórico em erupções vulcânicas na Toscana, Itália, como boratos na kernita (Na2B4O7.4 H2O) e na colemanita (Ca2B6O11.5 H2O) na Califórnia, Estados Unidos da América.

As amostras geralmente contêm isótopos na razão 19,78% de 10B para 80,22% de 11B.

A extração é possível por redução de fase vapor de tricloreto de boro com hidrogênio sobre filamentos eletricamente aquecidos.

O boro amorfo pode ser obtido por redução do trióxido com pó de magnésio.

Quando aquecido o boro reage com oxigênio, halogênios, ácidos oxidantes e álcalis fortes.

É usado em semicondutores e em filamentos na indústria aeroespacial.

O boro produz chama verde. O isótopo 10B é usado em fios e chapas de proteção para controle de reatores nucleares.

O elemento foi descoberto em 1808 por Sir Humphry Davy e por J. L. Gay – Lussac e L. J. Thenard.

Estrutura atômica

Boro

Número de níveis de energia: 2

Primeiro Nível de energia: 2
Segundo Nível de Energia: 3

Usos

Boro amorfo é usado como um dispositivo de ignição do combustível de foguetes e em foguetes pirotécnicos.

Ele dá as chamas uma cor verde característica.

Os compostos mais importantes de boro são bórico (ou bórico) ácido, bórax (borato de sódio) e óxido bórico.

stes podem ser encontrados em gotas para os olhos, anti-sépticos leves, detergentes em pó e esmaltes de cerâmica.

Bórax usado para ser usado para fazer lixívia e como conservante de alimentos.

Óxido bórico também é comumente usado na fabricação de vidro de borosilicato (pirex). Isso torna o vidro resistente e resistente ao calor. Têxteis de fibra de vidro e isolamento são feitas de vidro borosilcate.

Octaborato de sódio é um retardador de chama.

O isótopo boro-10 é bom em nêutrons absorventes. Isto significa que pode ser utilizado para regular a reatores nucleares.

Tem também um papel nos instrumentos utilizados para detectar neutrões.

Propriedades físicas

Uma das propriedades incomuns do boro é as muitas formas físicas, chamadas allotropes, em que ocorre.

Alótropos são formas de um elemento com diferentes propriedades físicas e químicas.

Uma forma de boro consiste em cristais vermelhos claros, com uma densidade de 2,46 gramas por centímetro cúbico.

Uma segunda forma consiste em cristais preto com uma aparência metálica e uma densidade de 2,31 gramas por centímetro cúbico.

Boro também pode ocorrer como um pó castanho com nenhuma estrutura cristalina.

A densidade deste pó é 2.350 gramas por centímetro cúbico.

Todas as formas de boro têm pontos de fusão muito elevados, a partir de 2.200 a 2.300 ° C (4.000 a 4.200 ° F).

Uma propriedade de especial importância é a capacidade do boro para absorver nêutrons. Os nêutrons são partículas subatômicas com que ocorrem no núcleo de quase todos os átomos sem nenhum custo. Átomos de boro são capazes de absorver uma grande número de neutrões. Isso faz com que o boro úteis nas hastes de reatores nucleares de controlo.

Um reator nuclear é um dispositivo para gerar energia a partir de reações de cisão nuclear.

Fissão nuclear é o processo em que grandes átomos são divididos, liberando grandes quantidades de energia e átomos menores.

Em um reator nuclear, é essencial que apenas o número certo de nêutrons estão presentes.

Demasiados nêutrons pode causar uma reação de fissão para ficar fora de controle. Muito poucos nêutrons e um pára reação de fissão.

Barras de controlo são longos tubos cheios de boro (ou algum outro elemento). As hastes podem ser levantado e abaixado no reator. Como as hastes são reduzidos para o núcleo, o boro absorve neutrões, retardando a reação.

Propriedades quimicas

Boro combina com o oxigênio no ar para formar trióxido de boro (B 2O3). Trióxido de boro, forma uma película fina sobre a superfície que impede a continuação da reação com oxigênio.

Boro não é solúvel em água. É normalmente não reage com os ácidos.

Na forma de pó, que reage com ácido nítrico quente (HNO3) e de ácido sulfúrico quente (H2SO 4).

Também se dissolve em fundido (derretido) metais.

Fonte: www.rsc.org/www.cdcc.sc.usp.br/www.chemicalelements.com/www.chemistryexplained.com

 

 

 

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