Hòa tan hoàn toàn 0,3g hỗn hợp hai kim loại X và Y ở hai chu kì liên tiếp, tác dụng hết với dung dịch HCl dư thu được 4,48 lít khí H₂(đktc). Tìm hai kim loại đó

Chọn câu trả lời đúng:

1. Ba nguyên tử X, Y,Z có tổng số đơn vị điện tích hạt nhân bằng 17. Tổng số electron trong ion là (X₃Y)^-2 là 32. Nhận xét nào sau đây không đúng:

A. X, Y, Z thuộc cùng nhóm chu kì B. X, Z thuộc cùng một nhóm

C. Z thuộc nhóm IA D. Y thuộc nhóm IVA

2. Theo quy luật biến ggooir tính chất các đơn chất trong bảng tuần hoàn thì:

A. phi kim mạnh nhất là iot B. kim loại mạnh nhất là Li

C. phi kim mạnh nhất là oxi D. kim loại mạnh nhất là flo

3. Cho ₂₀Ca, ₁₂Mg, ₁₃Al, ₁₄Si, ₁₅P. Thứ tự tính kim loại tăng dần là:

A. P, Al, Mg, Si, Ca B. P, Si, Al, Ca, Mg C. P, Si, Mg, Al, Ca D. P, Si, Al, Mg, Ca

4. So sánh nào sau đây sai:

A. tính phi kim P<N<O<F B. tính kim loại K>Mg>Al>Si

C. tính axit H₂SO₄>HNO₃>H₃PO₄>HClO₄ D. bán kính K>Na>Mg>Al³⁺

5. X, Y, M là 3 nguyên tố liên tiếp nhau (Z_x<Z_y<Z_m) trong cùng 1 chu kì. Y có cấu hình e lớp ngoài cùng là 3s²3p⁴. Dãy sắp xếp theo thứ tự tăng dần độ mạnh các axit tương ứng với các oxit cao nhất của X, Y, M là

A. H₂XO₄<H₃YO₄<HMO₄ B. H₂YO₄<HMO₄<H₃XO₄

C. HMO₄<H₂YO₄<H₃XO₄ D. H₃XO₄<H₂YO₄<HMO₄

6. Oxit cao nhất của một nguyên tố R ứng với công thức R₂O₇. Nguyên tố R có thể là

A. nitơ(Z=7) B. cacbon(Z=6) C. clo(Z=17) D. lưu huỳnh(Z=16)

Chia động từ trong ngoặc ở thì quá khứ đơn hoặc quá khứ hoàn thành:

1. My father (tell) me he (give) up smoking

2. He (be) late because he (have) an accident

3. I (come) to tell him they were the wrong seeds, but he (plant) them already

4. It had been raining in the night, the ground (be) wet

5. Mr John (be) in England for four years when the new government (come) to power

6. A man who (be attacked) by bandits was lying bleeding on the road

7. I now (have) to leave the house where I (spend) so many happy days

8. Although he (make) some mistakes, he (be considered) good enough for promotion

9. He (want) to find out whether you arrive

10. He (be treated) like a slave, so he (resign)

Chọn từ có trọng âm khác:

1. A. foreigner B. develop C. extremely D. together

2. A. enjoy B. study C. differ D. suffer

3. A. improve B. result C. become D. answer

4. A. background B. secondary C. private D. career

Chọn câu trả lời đúng:

1. Young people are usually full of...., but lack of experience

A. enthuse B. enthusiasm C. enthusiast D. enthusiastic

2. Ambulances arrived at the scene of the accident and took...to hospital

A. the sick B. the poor C. the injured D. the old

3. There...a hotel opposite the station but it closed a long time ago

A. used to be B. is C. use to be D. isn't

4. He was eager....his homework

A. doing B. to do C. that he was doing D. he was doing
5. Although floods destroy many things, they also make the....richer

A. ground B. globe C. soil D. earth

6. I think it is time to concentrate our great effort....improving education

A. in B. of C. on D. with

7. They live....their retirement pension

A. for B. of C. on D. with

8. I've never enjoyed going to the ballet or the opera; they are not really my....

A. piece of cake B. chip off the old block

C. biscuit D. cup of tea

9. Peter is......in his new job

A. interest B. interesting C. interested D. to interest

10. At last, Mary claimed that she had no gift for music,....made her parents disappointed

A. that B. these C. for which D. which

Chọn câu trả lời đúng:

A computer is an electronic..(1).. which executes software programs. It consits..(2)..2 parts hardware and..(3)..The computer processes input through input devices like mouse and keyboard. The computer displays output through output devices like color monitor and printer. The size of a computer varies considerably from very..(4)..to very big. The speed of computers also has a very large range. Computers have become indispenable in today's world. ..(5)..of people use computers all over the world

1. A. device B. computer C. monitor D.form

2. A. for B. with C. of D.about

3. A. mouse B. keyboard C. screen D. software

4. A. slim B. small C. large D. heavy

5. A. millions B. thousands C. hundreds D. none

Chọn câu trả lời đúng:

1. During rush our, streets are often crowded.....people and vehicles

A. for B. of C. with D.in

2. This is the most....film I have ever watched

A. excitement B. exciting C. excite D. excited

3. Without the pull of the Earth, we could not.....anything

A. weigh B. weight C. weightless D. weightlessness

4. For....did you organise the party?

A. who B. whom C. what D. which

5. He failed....his boss to accept his project

A. persuade B. to persuade C. persuading D. persuaded

6. Could you tell me the....time when the meeting begins?

A. exacting B. exactly C. exactness D. exact

7. She passed the exam, .....makes her parents happy

A. which B. when C. that D.who

8. The light....out while we were having tea

A. had gone B. was going C. went D. has gone

9. She was given an award for her services to.....

A. disable B. disabled C. the disable D. the disabled

10.....about early Chinese labraries

A. little is known B. to know little C. that little knows D. little knows

Sửa lỗi sai:

1. We (must) take (better) care of (old) in our (country)

2. (Everyday) Lan (has) breakfast (then) she (go) to school

3. (In spite of) she (was) sick, she (went) to school (on foot)

Chia động từ trong ngoặc ở thì quá khứ đơn:

1. He (do) nothing before he saw me

2. He thanked me for what I (do)

3. I (be) sorry that I had hurt him

4. After they had gone, I (sit) down and (rest)

5. As soon as you (go), I (want) to see you again

6. Before you (go) very far, we found that we (lose) our way

7. He (die) after he (be) ill a long time

8. My friend (not see) me for many years when I met him

9. In England he soon remembered all he (learn)

10. When the airplane landed, the pilot (find) that one of the wings (be damaged) by a shell

Chia động từ trong ngoặc ở thì hiện tại hoàn thành hoặc thì hiện tại hoàn thành tiếp diễn:

1. I (not see) you for a long time

2. You must tell me what you (do) since I last saw you

3. He (not be) here since Christmas I (wait) for him for two weeks

4. I (try) to learn English for years, but I (not succeed) yet

5. We (live) here for the last six months, and just (decide) to move

6. You already (drink) three cups of tea since I (sit) here

7. I (wait) here for her since 7 o'clock and she (not come) yet

8. Mary (rest) in the garden all day because she (be) ill

9. How long you (learn) English?

10. You must wake her! She (sleep) soundly for 10 hours!

Hợp chất khí với hiđro của nguyên tố có công thức RH₄, trong oxit cao nhất thì oxi chiếm 72,73% theo khối lượng. Tìm R

Oxit cao nhất của một nguyên tố là RO₃, trong hợp chất của nó với hidro có chứa 5,88% hiđro về khối lượng. Tìm R