Bài 1. Viết CTHH và tính Phân tử khối của các chất sau. Đồng thời cho biết chất nào là đơn chất, hợp chất. a) Khi etan, biết trong phân tử có 2C, 6H. b) Nhôm oxit, biết trong phân tử có 2Al và 30. c) Kim loại sắt d) Natri hidroxit (gồm 1Na, 10, 1H) e) Khí clof) Khí hidro g) Lưu huỳnh h) Axit nitric (gồm 1H, IN, 30) i) Khi nitơ j) Than (chứa cacbon) k) Giấm ăn (gồm 2C, 4H, 20). k)Giấm ăn (gồm 2C, 4H, 2O) I) Đường saccarozo ( gồm 12C, 22H, 110). m) Phân ure ( gồm 1C, 4H, 10, 2N). n) Kim loại Kēm o) Khí oxi p) Photpho

Cho a=11...1 (2n chữ số 1) ,b= 44...4 ( n chữ số 4 ). CMR A=a+b+1 là số chính phương

Anh/chị nghĩ gì về văn hoá đọc của giới trẻ ngày nay? ( Bài văn dài không quá 1000 từ )...làm giúp mình với ạ..các bạn lấy ở đâu cũng được trừ trên mạng ,mình cảm ơn ạ

Give the correct form of the verbs in brackets: used to + V or simple past. 1. I (see) ........... Marcus at the library working hard. He told me to say hello to you. 2. She (be) ............... a lot happier, but then she lost her job. 3. There (be) ............... three restaurants in this town, but two closed down leaving only one. 4. If you look over there, you can see the field where they (fight) ............. the Battle of Harris Hill in 1509. 5. Did you (take) ............. a lot of photos when you were in Moscow last year? 6. How many hours a day did you (go) ...............to school when you were ten? 7. Children never (talk) ............ so aggressively to their parents. It’s terrible! 8. Soldiers (build) .............. this bridge near the end of the Second World War. 9. Your mother (have) .................. a Yorkshire Terrier when she was a young girl, didn’t she? 10. When I was five, I (be) .............. able to do incredible gymnastics. Now I can’t even touch my toes. P/s: Giúp mình với mn ơi, VOTE 5 SAO nhé :((

Giúp mik với các bạn ơii!! Bài 3,4 nha các bạn.

Ảnh hưởng tiêu cực nền kinh tế xã hội

Giúp mình với. Ai làm nhanh nhất mình vote 5 sao

17-|x-7|=-5 3-(17-x)=189-(36+189) Giải hộ mình

giải hộ mình trang này dc ko ngắn mà. Mình cảm ơn

GIẢI DÙM MÌNH VỚI III Write a sentence with IF for each situation. Type II 1. The wind is blowing hard, so I can’t take the boat out for a ride. _______________________________________________________________ 2. I can’t take much exercises because I don’t have enough free time. _______________________________________________________________ 3. You learn hard. You get the scholarship. _______________________________________________________________ 4. Today isn’t Sunday. The pupils don’t have school off. ______________________________________________________________ 8. She can’t buy that bike. She doesn’t have enough money. _____________________________________________________________ 5. John isn’t intelligent. He can’t solve that math test. ______________________________________________________________ 6. The match can be cancelled because it rains heavily. _______________________________________________________________ 7. My parents do not allow me to do, so I have to stay at home. ___________________________________________________________ 8. Peter doesn't study hard, so he can't get good marks. _____________________________________________________________ 9.People don't realise how important it is to conserve energy, so they do nothing about it. __________________________________________________________ 10. There isn't any truth in her allegations, so I won't resign. __________________________________________________________