Cho mô hình nguyên tử của nguyên tố nitrogen (N) như sau:
Số proton và số electron lớp ngoài cùng của nguyên tử N lần lượt là
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Cấu hình electron của N là $1s^22s^22p^3$.
Lớp ngoài cùng là lớp thứ 2, có $2s^22p^3$, tổng cộng có $2 + 3 = 5$ electron.
Câu hỏi liên quan
Cho hình bình hành ABCD và một điểm S không nằm trong mặt phẳng (ABCD). Giao tuyến của hai mặt phẳng (SAB) và (SCD) là một đường thẳng song song với đường thẳng nào sau đây?
Logical thinking and problem solving: Choose A, B C or D to answer each question.
Which of the following is a generalisation about an animal?
Đâu là dấu hiệu để nhận biết pháp luật là một trong những đặc điểm để phân biệt pháp luật với đạo đức?
Read the following passage about Unconventional Teachers Who Changed Lives 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.
Traditional education focuses on textbooks, but some teachers go beyond these limitations. Mrs. Rodriguez transformed her classroom into a living laboratory. Her students conducted experiments with plants and simple machines. She believed hands-on learning creates deeper understanding than reading alone. When asked why she taught differently, she replied, "I want students to fall in love with discovery." Her methods helped struggling students improve and develop passion for science.
Mr. Jackson abandoned lectures for storytelling and role-playing. His students experienced history by acting out important moments. This approach made history come alive and helped them remember key information. One student said, "Before Mr. Jackson's class, I thought history was boring, but he showed us it's fascinating." He took classes to historical sites and invited veterans to share experiences. These connections helped students understand how past shapes our present.
In a remote village, Ms. Chen taught English without proper textbooks. She created materials using newspapers and song lyrics. Despite limited resources, her students achieved remarkable results through her dedication. "Learning should be joyful, not painful," she told questioning parents. Ms. Chen organized conversation clubs and pen pal exchanges. These activities gave students practical language skills and confidence to use English in real situations.
Coach Williams was a life mentor who taught valuable lessons through sports. He focused on teamwork and fair play rather than winning. Students who struggled academically often excelled in his class. "The playing field is where children learn who they truly are," he explained. He created inclusive activities for all students regardless of athletic ability. Many former students credit him with teaching life skills like resilience and cooperation that helped them succeed after graduation.
Which of the following is NOT mentioned as a teaching method used by these unconventional teachers?
Các nước phát triển tập trung chủ yếu ở khu vực 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.
Boosting Your Confidence
Looking to improve your self-esteem and feel more confident in your daily life? Here’s how you can make positive changes!
Confidence Facts: Studies show that only 35% of people report feeling confident in their abilities, while others ___(7)___ with self-doubt. Building confidence can help improve your performance at work and in social situations.
Tips to Boost Your Confidence:
● Set realistic goals! Start small and ___(8)___ yourself when you reach milestones.
● Surround yourself with positivity! Seek ___(9)___ supportive friends and colleagues to boost your self-esteem.
● Focus on your strengths! ___(10)___ dwelling on mistakes, concentrate on what you do well.
● Practice self-care! Taking time for yourself can ___(11)___ your mood and confidence levels.
● Keep learning! Gaining new skills helps ___(12)___ a sense of accomplishment.
Sinh vật nào sau đây được sử dụng để thu nhận Streptokinase?
Điền vào chỗ trống.
Cho bảng số liệu sau:
DIỆN TÍCH RỪNG VIỆT NAM GIAI ĐOẠN 1943 - 2021
(Đơn vị: triệu ha)
1943
2010
2015
2021
Tổng diện tích rừng
14,3
13,4
14,1
14,7
- Diện tích rừng tự nhiên
14,3
10,3
10,2
10,1
- Diện tích rừng trồng
0
3,1
3,9
4,6
(Nguồn: Tổng cục Thống kê năm 2022)
Căn cứ vào bảng số liệu trên, diện tích rừng trồng chiếm......... % tổng diện tích rừng năm 2021.
(Làm tròn đến số thập phân thứ 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 31 to 40.
Mountain Lions Amid Wildfires: A Struggle for Survival
Beth Pratt, the California director for the National Wildlife Federation, has spent her career protecting Los Angeles’ mountain lions. These top predators live in a rocky area surrounded by fancy houses and many roads. When wildfires destroy vast stretches of open land, the survival options for these animals become critically limited. “This is the LA area—these mountain lions can’t just move into the Kardashians’ backyard,” Pratt says, her voice filled with concern for the animals in such a difficult situation.
(I) The chaparral vegetation, covering about 10% of California, is one of the world’s most flammable ecosystems. (II) In Los Angeles, suburban sprawl intrudes on these areas, blocking wildlife escape routes. (III)Fires strip the land of food and shelter, transforming vibrant ecosystems into barren landscapes. (IV) Pratt highlights the urgency of the situation, explaining how areas that once supported life are now “taken out of commission,” leaving many species to starve or struggle for survival.
The consequences extend beyond wildlife. Wildfires have caused devastating human losses, with 88,000 people evacuated and a rising death toll of 25. Meanwhile, the non-human world suffers equally, particularly endangered species with limited ranges. Red-legged frogs, reintroduced into Santa Monica streams in 2014, are among the most affected, with their habitats repeatedly destroyed. The Woolsey Fire of 2018 was followed by mudslides that wiped out much of the region's delicate ecosystem, and scientists fear similar outcomes this time. California newts, reptiles, and snakes are also at high risk, while mammals and birds, although more likely to escape, face challenges in finding food and shelter as the ecosystem bounces back.
Despite the devastation, hope remains. The chaparral is a fire-adapted ecosystem, and life often endures beneath the soil. Seeds can survive and germinate quickly, with grasses sprouting weeks after the first rain. Shrubs may take up to a decade to recover, depending on rainfall. Prof. Stefan Doerr, an expert on wildfires, emphasizes the resilience of this landscape, noting its evolutionary adaptation to high-intensity fires occurring every 30 to 100 years. While the aftermath looks bleak, these fires play a role in maintaining biodiversity, offering a glimmer of hope for recovery.
Where in the passage does the following sentence best fit in paragraph 2?
“Composed of grasslands, shrubs, and woody species that regenerate after intense wildfires, this habitat faces escalating threats.”
Tính cách khẳng khái nóng nảy của Ngô Tử Văn được thể hiện qua những hành động như thế nào?
Một chiếc thuyền chuyển động ngược dòng với vận tốc 14 km/h so với mặt nước. Nước chảy với vận tốc 9 km/h so với bờ. Vận tốc của thuyền so với bờ là
Thiết bị nào dưới đây có khả năng diệt khuẩn, tiệt trùng các dụng cụ trong phòng thí nghiệm?
Ở động vật có các tổ chức thần kinh, hệ thần kinh tiến hóa nhất là gì?
Nguồn năng lượng sinh ra ngoại lực chủ yếu là của yếu tố nào?
Với sự phát triển kinh tế - xã hội của một số quốc gia, nguồn lực có vai trò quan trọng nhất là gì?
Trong không gian Oxyz, hình chiếu vuông góc của điểm \(A(3;4;-5)\) trên trục Oy là điểm nào dưới đây?
Cho parabol \(y = a{x^2} + bx + c\) có đồ thị như hình vẽ dưới đây. Khẳng định nào dưới đây đúng?
Tính góc tạo bởi giữa hai đường thẳng:
d1: 2x - y - 10 = 0 và d2 : x - 3y + 9 = 0
Read the following passage about Champions of the Overlooked 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 18 to 22.
In every community, there are special people who help those who cannot speak for themselves. These champions work tirelessly to bring attention to forgotten issues and overlooked individuals. They believe that every person deserves dignity and respect, regardless of their circumstances. Animal rights activists are dedicated individuals (18)_________. Many homeless people are ignored by society, but they deserve our attention and support. Children with disabilities often face barriers to education; however, dedicated teachers create inclusive classrooms for all students. The elderly share their wisdom and experience while needing our care and respect. If more resources were provided, (19)_________. Environmental defenders protect natural habitats and speak for future generations who will inherit our planet. They monitor pollution levels, plant trees, and educate communities about sustainability. These champions often work without recognition, (20)_________.
Volunteers at animal shelters provide food, medical care, and love to abandoned pets. (21)_________. Many of these helpers also advocate for stronger animal protection laws and better education about responsible pet ownership. Their dedication shows us how much impact one person can have on many lives. (22)_________. Their work reminds us that true humanity means caring for all living beings, especially those who cannot advocate for themselves. By supporting these champions, we too can help build a more compassionate and inclusive society where everyone is valued and heard.
It is unnecessary for you to finish the report until tomorrow morning.