Nguyên tử của nguyên tố M có số hiệu nguyên tử là 8. Số electron độc thân của M là
Nguyên tử của nguyên tố M có số hiệu nguyên tử là 8. Số electron độc thân của M là
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Ở lớp ngoài cùng (lớp 2) có 6 electron, trong đó có 4 electron ở phân lớp p.
Ta có $2p^4$ có cách điền electron vào 3 orbital p như sau: $\uparrow\downarrow$ $\uparrow$ $\uparrow$. Vậy có 2 electron độc thân. Tuy nhiên, câu hỏi hỏi số electron độc thân của M, mà M là nguyên tử nên số electron = 8, và số proton = 8. Khi nguyên tử M tạo thành ion, số electron độc thân có thể thay đổi, nhưng trong nguyên tử M thì chúng ta xét cấu hình electron của nguyên tử M.
Số electron độc thân của M là 2.
Câu hỏi liên quan
Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questionsfrom 13 to 17.
a. Mom: Don’t spend too much time playing video games. You should focus on your studies.
b. Mom: That’s good. Remember, education comes first.
c. Son: I understand, Mom. I will only play after finishing my homework.
Số electron tối đa trên mỗi phân lớp ns, np, nd, nf lần lượt là
Cho bảng số liệu lưu lượng nước các tháng năm 2023 của sông Hồng tại trạm Sơn Tây, đơn vị: m3/s (nguồn Niên giám thống kê 2023, Nxb Thống kê, 2024):
Theo bảng số liệu và dựa vào kiến thức đã học, phát biểu nào sau đây đúng về chế độ nước sông Hồng tại trạm Sơn Tây.
Ý kiến nào sau đây chính xác nhất?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
SCREEN TIME: MENTAL HEALTH MENACE OR SCAPEGOAT?
"Have smartphones destroyed a generation?" Jean Twenge - a psychology professor at San Diego State University - asked in her controversial book, iGen. In the book, she argues that those born after 1995 are facing "a mental-health crisis", and she believes it can be linked to growing up with their noses pressed against a screen. Her newest study provides more support for that connection, showing that teens who spent more than an hour or two a day interacting with their gadgets were less happy on average than those who had more face time with others.
Twenge's conclusions have come up against criticism in the past. Some have accused her work of oversimplifying or overlooking data that may tell a slightly different story. Twenge recognises that her study suggests only a link between screen use and psychological well-being. A possible explanation is that kids are running to their screens to escape from the things in life that are making them unhappy. However, the surveys can't say whether screen time directly changes teens' mental health, the research states.
Philanthropist Melinda Gates, whose three children were also born after 1995, wrote in The Washington Post, "phones and apps aren't good or bad by themselves, but for adolescents who don't yet have the emotional tools to overcome life's problems, they can aggravate the difficulties of growing up."
At the same time, she said, kids are learning on their devices and connecting in novel ways. Other studies have explored the connection between social media and isolation and how "likes" activate the brain's reward centre. Some analyses have found that moderate use of these technologies is not harmful in itself and can even improve children's social skills and build emotional strength.
Which of the following is NOT true, according to the passage?
Đặc điểm nào tương ứng với giai đoạn lọc trong quá trình hình thành nước tiểu ở nephron?
Sử dụng các kí hiệu đoạn, khoảng, nửa khoảng để viết tập hợp A={x∈R7≤x≤10}.
Lúc 8h sáng một người đi xe khởi hành từ A chuyển động thẳng đều với tốc độ 40 km/h. Người đó sẽ cách A 60 km vào lúc mấy giờ?
Hệ thống chính trị của nước ta được tổ chức và hoạt động theo mấy nguyên tắc cơ bản?
Em hãy điền cụm từ thích hợp vào chỗ trống (….) trong khái niệm sau đây: “Thị trường lao động là nơi diễn ra các quan hệ thoả thuận giữa ……………… về tiền lương, điều kiện làm việc trên cơ sở hợp đồng lao động”.
Hóa học là ngành khoa học thuộc lĩnh vực
Các nước có GDP/người cao tập trung nhiều ở khu vực nào?
CHỦ ĐỀ: GIẢI NOBEL HÓA HỌC 2020
(Tham khảo bài văn của chủ đề trong đường link dưới đây ở trang 21)
https://tvsthpt.dlib.vn/app/doc-sach-ebook/d00ddd794efd
Và trả lời câu hỏi sau:
Theo đoạn [4] và [5], có thể điều trị khỏi các bệnh di truyền do đột biến gen khi áp dụng công cụ CRISPR/Cas9 để tăng cường hệ miễn dịch của vi khuẩn nhằm kháng lại virus tấn công từ bên ngoài.
Đúng hay sai?
Trong đoạn 1, màu sắc và văn hóa Tây Nguyên thể hiện qua những yếu tố nào?
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.
Grand Opening of TIEU MINH Supermarket!
Welcome to the brand-new TIEU MINH Supermarket, where unbeatable offers await you! Join us as we celebrate our grand opening with special deals and discounts on a wide (7)_______of essentials, from groceries to household appliances and more!
Here’s what you can look forward to:
• Amazing discounts on a vast amount of products, including fresh foods, kitchenware, storage solutions, and (8)______ items.
• Exclusive “Buy One, Get the Other at 20% Off” deals on select items.
• A lucky draw with the chance to win (9)______for your home, perfect for upgrading your storage and kitchen spaces!
(10)______high prices, the items will be offered at a 30-50% discount without compromising quality. (11)______at our grand opening event to enjoy free samples, interactive games, and live demos from top brands. Our rewards program also lets you earn points and receive exclusive member(12)_______.
Ý nào sau đây là thuộc đặc điểm của cho vay tín chấp?
Read the passage carefully. Choose an option (A, B, C or D) that best answers each question from 16 to 22.
1. Like many emergency responders, Nicholas Groom is used to stress at work. On the one hand, the stress can be helpful. “I find that when attending a serious incident, it helps me to maintain focus on the situation,” Nicholas Groom said. On the other hand, the work can be highly pressurized. “Too much stress can impair your ability to make decisions,” he adds. And Groom is not alone in his complicated relationship with stress.
2. Many people believe that there should be a balanced amount of stress. In other words, not too much stress so you’re not overwhelmed but not too little stress so you don’t feel unmotivated. After all, some anxiety is motivating; think of the adrenaline before a deadline or the excitement before a competition. Sports fans sometimes even talk about a “gene” in some athletes who seem to play best in the decisive final moments of a match. Furthermore, many psychologists claim that performance in many situations increases with stress up to a point. Of course, any stress can cause harm when it’s prolonged. To take just one example, a long-term high heart rate is linked to cardiovascular diseases. And additional stressors, such as financial pressures or psychiatric issues, clearly affect how beneficially someone can respond to stress.
3. So is there a way to harness stress to your advantage while being mindful of its detrimental long-term effects? One key factor is to avoid, whenever possible, the point when stress leads to mental and physical collapse. Crystal Wernicke, 30, has always used stress as a motivator. But juggling between parenting, a full-time job, a voluntary role and financial troubles at the same time became too much and eventually led to a two-month period of illness. Another factor is the presence of control. For those who feel powerless over their situation, stress is unlikely to be beneficial. But with some autonomy over stressful tasks, we are better able to convert that pressure into higher performance.
4. When it comes to stress and how it affects your performance, it’s helpful to recognize the variations in personality, type of stress and task that affect the level of pressure you are under, as well as understanding tools you can use to control and harness that stress. Ultimately, it’s not helpful to take a one-sided view, either demonizing or glorifying stress. As James C Quick, a management professor at the University of Texas, sums up: “Stress can be the kiss of death as well as the spice of life.”
What is one way to harness stress to your advantage, according to the third paragraph?
Hệ quản trị cơ sở dữ liệu (CSDL) là phần mềm như thế nào?
Mark the letter A, B, C or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 27 to 31.
Speech is one of the most important ways of communicating. It consists of far more than just making noises. To talk and also (27) ___________ by other people, we have to speak a language, that is, we have to use combinations of sounds that everyone agrees to stand for a particular object or idea. Communication would be impossible (28) _________________. Learning a language properly is very important. The basic vocabulary of English is not very large, and not only about 2,000 words are needed to speak it quite well. But (29) ________________, the more precise you can be about their exact meaning. Words are the main thing we use in communicating what we want to say. (30) ________________. (31) _______________ of voice can express many emotions and show whether we are pleased or angry, for instance.
How do we know who the woman in the Mona Lisa is?