Đáp án:
$nH_{2}=\frac{0,2}{2}=0,1$
Số nguyên tử Hidro=0,1.6.$10^{23}$=0,6.$10^{23}$
Giải thích các bước giải:
$n_{H_2}=\frac{0,2}{2}=0,1 mol$
$\Rightarrow n_H=2n_{H_2}=0,2 mol$
Số H: $0,2.6.10^{23}= 1,2.10^{23}$
Bạn vẽ hình rồi làm đầy đủ giúp mình nhé! Mình sẽ vote 5 sao cho bạn có câu trả lời nhanh nhất và chính xác nhất nè
Giúp em từng này câu tiếng anh nhé
$\frac{7}{6}$ < x-$\frac{2}{3}$ <$\frac{26}{9}$
Lm giúp mình vs ạ Cảm ơn :)))
cho Parabol (P) : y = x^2 và đường thẳng (d) :y = 4x+ 2m^2-1 ,với m là tham số a) Chứng minh rằng (d) luôn cắt (P) tại 2 điểm phân biệt với mọi m b) Gọi A( x1,y1), B(x2,y2) là tọa độ giao điểm của (d) và (P) . Tìm m để (y1−2m^2+4)(y2−2m^2+4)=−55
Tìm giá trị ng nguyên của x để biểu thức: B=8-x phần x-3 có giá trị nhỏ nhất. Giúp e vs ạ
Cho Δ ABC có ba góc nhọn nội tiếp (O;R). Giả sử các điểm B,C cố định và A di động trên (O) sao cho AB < AC < BC. Đường trung trực của đoạn thẳng AC cắt AB và BC lần lượt tại M và N. Chứng minh: OM.ON = R2. Bốn điểm M,N,P,Q cùng nằm trên một đường tròn. Giả sử hai đường tròn ngoại tiếp Δ BMN và Δ CPQ cắt nhau tại S và T. Chứng minh ba điểm S,T,O thẳng hàng.
Nhận xét tình hình nước ta trong thời kì dựng nước
tìm các số a3b -cùng chia hết cho 3 và 5
Exercise 1: Find the word which has a different sound in the part underlined 1. A. beds B. clocks C. walls D. tables 2. A. mothers B. centres C. aunts D. cousins 3. A. cities B. watches C. dishes D. houses 4. A. grandparents B. brothers C. uncles D. fathers 5. A. books B. walls C. rooms D. pillows 6. A. poster B. sofa C. own D. laptop 7 A. fridge B. light C. picture D. living 8. A. television B. toilet C. bed D. chest 9. A. book B. look C. door D. room 10. A. clocks B. villas C. tables D. chairs Exercise 2: Put the words into THREE groups (/ s /, / z / and / iz /) books, doors, windows, boards, clocks, bags, pencils, desks, schools, classrooms, students, teachers, couches, benches, glasses, brushes, maps, sinks, beds, caculators, villars, lamps - / iz/ : ………………………………………………………………………………………………….. - /s/: ………………………………………………………………………………………………….. - /z/: ………………………………………………………………………………………………….. Exercise 3: Add “ my, your, I, you, he, she, her, they”( more than one answer): 1. ________live on Le loi street 2. Hello, ________name is Minh 3. What’s________ name?. My name’s Nam 4. Where do________live? 5. How old are________? 6. This is Nam. ________ is a student 7. My new classmate is Mai. ________is in class 6A. 8. ________ am 12 years old 9. I have 2 friends. ________are Nam and An 10. How do ________ spell it ? H_O-A Exercise 4: Choose the best answer: 1. Maryan is ………….. home today (at/ on / between/ in) 2. The bank is ……………… the supermarket (on / in / next to/ between) 3. The drug store is between the hospital ………….the toy store (at/ and / between/ in) 4. What is there in the bedroom? (cupboard/ shower / bed/ dishwasher) 5. There is ……………. television in the living room (a/ an / in / on) 6. ………….the left of the house, there is a garden. (In/ To/ Of/ On) 7. ………………..…. markets are there in your hometown? (How often/ How old / How many/ What ) 8. Thet cat is ………….the table (at/ on / between/ in) 9. I ………………TV every day. (watches / watch/ to watch/ watching) 10. Mary ………….. go to school by bike. (going/ go / goes / to go) Exercise 5: Complete the sentences with suitable prepositions of place. 1. The picture is ………… the wall 2. The book store is …………… the toy store and the drug store. 3. Can you see the cat ……………the picture? 4. The child is hiding ………………the tree. 5. The book is……………… the left ……….the lamp. 6. My house is next ……………to the river. 7. Jone lives ……………..America. Exercise 6: Underline the mistakes and then correct it. 1. Where is the flowers? ……………………………………. 2. There are a park near Tuan’s house. ……………………………………. 3. The television is between to the telephone. ……………………………………. 4. The mountains are to the left in the house. ……………………………………. 5. My school have a big yard. ……………………………………. 6. Lan watchs TV everyday. ……………………………………. 7. What time do she get up? ……………………………………. 8. Mr.Quyen teach Engish at Yen Nhan secondary school……………………………………. 9. The students are in the classroom. …………………………………… Exercise 7: Give the correct form of the word given to complete the sentences. 1. I keep my socks in the bottom_______________. (DRAW) 2. I don’t attach any ___________to these rumours. (IMPORTANT) 3. Payment is _________________upon delivery of the goods. (CONDITION) 4. This story is apparently a complete ________________. (INVENT) 5. What a ____________ thing to say! (BEAUTY) 6. There’s no ___________________ in the results. (DIFFERENT) 7. Do you get many_________________? (VISIT) 8. Do you have any ideas? You’re the _______________one. (CREATE) Exercise 8: Give the correct form of the words in the blank (Using the present simple and present continuous). 1. Lan (not have) ______ many friends in her new school. 2. Hung (come) ______ from Ha Noi but he (stay) ______ with his relatives in Ho Chi Minh city at the moment. 3. We (not drive) ______ to work every day. We (go) ______ by bus. 4. Who you (talk) _______ to on the phone now, Minh? 5. Where your new friend (live) _________ Nga? -She (live) ________ on Hang Bai street. 6. you (be) ________ in class 7A? -No, I (be)________ in class 7D. 7. Look! Jane (play)_______ the guitar. This afternoon, she will play table tennis. 8. I (not talk) __________ to her at present 9. How often ________ she (go) ________ fishing? - She (go) _________ once a year. 10. (Be) _______your friends students? -Yes, they (be) _________
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