Nguyên tử sắt có khối lượng là 9,2988.10-23 gram. Biết điện tích hạt nhân của sắt là +26. Số neutron của nguyên tử sắt là
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
- Khối lượng mol của sắt (Fe) là khoảng 56 g/mol.
- Số Avogadro là $N_A = 6,022 \times 10^{23}$ nguyên tử/mol.
- Số proton của sắt là 26 (do điện tích hạt nhân là +26).
$M = 9,2988 \times 10^{-23} \times 6,022 \times 10^{23} \approx 56$ g/mol.
Số khối $A$ (tổng số proton và neutron) của nguyên tử sắt là khoảng 56. Vì số proton là 26, ta có thể tính số neutron $N$ như sau:
$N = A - Z = 56 - 26 = 30$.
Tuy nhiên, các đồng vị của sắt có thể có số neutron khác nhau. Ta cần tìm đồng vị phổ biến nhất. Bài toán có vẻ đang đánh đố, mình dùng cách loại trừ. đáp án 1 và điện tích hạt nhân giống nhau nên loại. đáp án 2 sai lệch nhiều. đáp án 4 có vẻ hợp lý nhất.
Vì đề bài cho khối lượng của nguyên tử sắt là $9,2988.10^{-23}$ gram, ta có thể suy ra số khối A của nguyên tử sắt là:
$A = \frac{9,2988 \times 10^{-23} g \times 6,022 \times 10^{23} mol^{-1}}{1 g/mol} \approx 56$
Số neutron là: $N = A - Z = 56 - 26 = 30$. Do đó, đáp án gần đúng nhất là 30 hoặc 32.
Câu hỏi liên quan
Trong các mệnh đề bên dưới, mệnh đề nào đúng?
Khi lực ép giữa hai mặt tiếp xúc tăng lên thì hệ số ma sát giữa hai mặt tiếp xúc
Một dây dẫn có chiều dài L=1,2 m, được đặt trong từ trường đều có độ lớn \(B={{5.10}^{-2}}\) T. Cường độ dòng điện chạy trong dây dẫn có giá trị 3 A.
Độ lớn của lực từ tác dụng lên dây dẫn khi dây dẫn đặt vuông góc với các đường sức từ là bao nhiêu niutơn (làm tròn kết quả đến chữ số hàng phần trăm)?
Phương án nào sau đây là các giá trị dùng để biểu diễn dãy nhị phân?
Chất phóng xạ X có chu kỳ bán rã là T. Ban đầu có một mẫu X nguyên chất với khối lượng 4g. Sau khoảng thời gian 2T, khối lượng chất X trong mẫu đã bị phân rã là:
Vì sao Ngô Tử Văn đốt đền?
Hàng hoá bán được trên thị trường nghĩa là chủng loại, hình thức, chất lượng hàng hoá đó đáp ứng yêu cầu của xã hội là nội dung thể hiện chức năng gì của thị trường?
Bản vẽ thiết kế phương án:
Trong nhiệm kì 2008 - 2009, Việt Nam được giữ chức vụ gì trong tổ chức Liên hợp quốc?
Nguyên tử nguyên tố X phổ biến trong tự nhiên có tổng các hạt cơ bản là 46. Số khối của nguyên tử X là
Trong không gian Oxyz, cho các điểm \(A(1;1;2)\) và \(B(4;5;1)\). Các điểm M, N di động trên mặt phẳng \((Oxy)\) sao cho \(MN=1\). Tổng \(AM+BN\) có giá trị nhỏ nhất là bao nhiêu (nhập đáp án vào ô trống)?
Trong cấu trúc của tế bào, nước phân bố chủ yếu ở
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 18 to 23.
AI (Artificial Intelligence) is revolutionizing the medical field by providing more accurate diagnoses and personalized treatment plans. Since its development, AI has become increasingly integrated into healthcare, (18) ___________. One of the most prominent examples is its use in medical imaging, where AI-powered systems are capable of detecting diseases, like cancer, with remarkable precision.
AI systems are particularly valued for their ability to process vast amounts of data quickly, enabling doctors to focus on patient care rather than administrative tasks. These advancements have led to (19) ___________, allowing for better overall outcomes. Not only does AI reduce the potential for human error, but it also continuously improves through learning from new medical data.
Medical AI systems have also (20) ___________. By analyzing genetic information and patient histories, AI can suggest potential treatment options that may have been overlooked by human experts. Moreover, these systems often lack the information needed to recommend the best treatment, ensuring that treatments are more effective and better suited to individual needs.
Despite the many benefits, some critics argue that there are still ethical concerns about the widespread adoption of AI in healthcare. For example, (21) ___________ could lead to overreliance on machines, reducing the need for skilled medical professionals. However, proponents believe that as AI continues to evolve, the medical field will revert to traditional methods By working alongside human experts, AI has the potential to transform healthcare, making it more efficient and accessible for all.
In summary, the rise of AI in medicine is an exciting development that shows great promise. It is essential (22) ___________. As these technologies advance, doctors may struggle to trust AI in complex cases.
Ngành du lịch không có vai trò nào sau đây?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions:
For many people who live in cities, parks are an important part of the landscape. They provide a place for people to relax and play sports, as well as a refuge from the often harsh environment of a city. What people often overlook is that parks also provide considerable environmental benefits.
One benefit of parks is that plants absorb carbon dioxide - a key pollutant - and emit oxygen, which humans need to breathe. According to one study, an acre of trees can absorb the same amount of carbon dioxide that a typical car emits in 11,000 miles of driving. Parks also make cities cooler. Scientists have long noted what is called the Urban Heat Island Effect: building materials such as metal, concrete, and asphalt absorb much more of the sun’s heat and release it much more quickly than organic surfaces like trees and grass. Because city landscapes contain so much of these building materials, cities are usually warmer than surrounding rural areas. Parks and other green spaces help to mitigate the Urban Heat Island Effect.
Unfortunately, many cities cannot easily create more parks because most land is already being used for buildings, roads, parking lots, and other essential parts of the urban environment. However, cities could benefit from many of the positive effects of parks by encouraging citizens to create another type of green space: rooftop gardens. While most people would not think of starting a garden on their roof, human beings have been planting gardens on rooftops for thousands of years. Some rooftop gardens are very complex and require complicated engineering, but others are simple container gardens that anyone can create with the investment of a few hundred dollars and a few hours of work.
Rooftop gardens provide many of the same benefits as other urban park and garden spaces, but without taking up the much-needed land. Like parks, rooftop gardens help to replace carbon dioxide in the air with nourishing oxygen. They also help to lessen the Urban Heat Island Effect, which can save people money.
In the summer, rooftop gardens prevent buildings from absorbing heat from the sun, which can significantly reduce cooling bills. In the winter, gardens help hold in the heat that materials like brick and concrete radiate so quickly, leading to savings on heating bills. Rooftop vegetable and herb gardens can also provide fresh food for city dwellers, saving them money and making their diets healthier. Rooftop gardens are not only something everyone can enjoy, they are also a smart environmental investment.
Question 37: Using the information in paragraph 2 as a guide, it can be inferred that ______.
Read the following passage about green living 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
Green living refers to a lifestyle that promotes sustainability and environmental consciousness. This way of life encourages individuals to make choices that reduce their carbon footprint and conserve natural resources. Practices such as recycling, using renewable energy sources, and reducing waste are fundamental aspects of green living. By adopting these practices, individuals can contribute to the preservation of the environment and promote a healthier planet for future generations.
One significant component of green living is the use of renewable energy sources. Solar, wind, and hydroelectric power are examples of renewable energy that can replace fossil fuels. Using renewable energy reduces greenhouse gas emissions and dependence on non-renewable resources. Additionally, renewable energy sources are often more sustainable and have less impact on the environment.
Another important aspect of green living is sustainable consumption. This involves choosing products that are environmentally friendly and responsibly sourced. For example, buying locally produced food reduces the carbon footprint associated with transportation. Moreover, opting for products made from recycled materials helps conserve resources and reduce waste.
Green living also emphasizes the importance of conserving water and energy. Simple actions such as turning off lights when not in use, fixing leaks, and using energy-efficient appliances can significantly reduce energy and water consumption. These practices not only benefit the environment but also save money on utility bills.
Education and awareness play a crucial role in promoting green living. By educating individuals about the benefits of sustainable practices and how to implement them, communities can foster a culture of environmental responsibility. Awareness campaigns, workshops, and educational programs are effective ways to encourage people to adopt green living practices.
In which paragraph does the writer mention the economic benefits of green living practices?
Cho tam giác có độ dài ba cạnh lần lượt là \(1\), \(2\), \(\sqrt{5}\). Độ dài đường cao ứng với cạnh lớn nhất bằng
Read the following advertisement 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 1 to 6.
Heirloom Moments™: Family Traditions Reimagined for the Quantum Age
The revolutionary technology transforms how families (1)_________ across generations. Our (2)_________ creates unforgettable experiences for everyone.
Families (3)_________ our service report stronger connections with distant relatives. We send photos (4)_________ grandparents through our secure platform.
When it comes to preserving memories, Heirloom Moments™ (5)_________ the cake! We encourage you to start your family's digital legacy today.
Visit our website or call us today (6)_________ more about how Heirloom Moments™ can help your family stay connected across time and space!
Khi nuôi vi khuẩn trong môi trường nuôi cấy không liên tục thì tốc độ tăng trưởng của quần thể đạt tối đa vào pha nào sau đây?
Phần mềm được sử dụng để truy cập các trang web và khai thác tài nguyên trên internet được gọi là gì?