Cho phản ứng sau: Fe₂O3 (s)+3H2(g)→2Fe(s)+3H2O(1). Biết nhiệt tạo thành chuẩn của Fe2O3, H₂O lần lượt là -824,2 kJ/mol,-285,8 kJ/mol Biến thiên enthalpy chuẩn của phản ứng là

Giúp mình với,cần gấp ạ Rewrite the following sentences without changing their meaning. Use the given word(s) if any. 1. He started working as a volunteer at an animal shelter two months ago. => He has..... 2. Having a part-time job will make you more financially independent. => If you....... 3. Carol was skiing in Switzerland. She met her old friend, Tim. => While...... 4. I felt that it had been a mistake to write to him. => I regretted......

Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage. Hi Kathy, I'm writing to you from Con Dao island, where I'm working as a volunteer for the International Union for Conservation of Nature (IUCN). I have just come here for two days but I have (1) oldest and largest global (2) since the mid-1980s. It (3). done so many things. Do you know that IUCN is one of the organisations? IUCN has worked in Vietnam to protect endangered wild animals, especially the sea turtles in Vietnam. In Con Dao island, many sea turtles swim to the islands between the fourth and seventh lunar months and lay their eggs in the sand before retuming to the sea. However, the number of sea turtles (4) over the last 30 years because of overfishing, pollution and destruction of nesting beaches. During the days, we have taken part in coastal clean-ups. At night, we have guarded turtle nests, protected eggs (5). poachers and released baby sea turtles back into the ocean early in the morning. It's hard work but it's enjoyable and I've met a lot of great people. The best part about working for IUCN is that I can help endangered animals and still have fun at the same time. I hope you're having fun, too. See you in a month. All the best, Hong Nguyen 1. A. never B. still C. already D. yet 2. A. environmental B. environmentalist C. environmentally D. environment 3. A. intend B. serve C. decides D. aims 4.A. decreased B. has decreased C. are decreasing D. decreases 5. A. with B. to C. from D. on Giúp mình với

Rewrite the following sentences without changing their meaning. Use the given word(s) if any. 1. He started working as a volunteer at an animal shelter two months ago. => He has 2. Having a part-time job will make you more financially independent. => If you 3. Carol was skiing in Switzerland. She met her old friend, Tim. => While 4. I felt that it had been a mistake to write to him. => I regretted

Cho ngtử K(Z=19) a) viết cấu hình electron nguyên tử và biểu diễn cấu hình theo ô orbital của nguyên tử Cl b)hãy cho biết Cl là nguyên tố s,p hay d?giải thích

Trong tự nhiên Ag có 2 đồng vị bền là ¹⁰⁷Ag và ¹⁰⁹Ag.Nguyên tử khối trung bình của Ag là 107,87.Tính phần trăm khối lượng của ¹⁰⁷Ag?

Write a paragraph (120-150 words) about one of your family routines. Use the following questions as cues for your writing. (2.0p) 1. What is the routine? 2. How often/When do you do it? 3. What are the activities? What does each family member do? 4. How do you feel about the routine?

cho 2 tập hợp số A=(m-1;m+4] và B=(-2;3] với m thuộc R.Xác định m để A là con của B