Dung dịch A là dung dịch muối nitrat của Mg2+ , Ba2+, Al3+ , Cr3+, Co2+, Ag+, Hg22+ - Thêm dung dịch NaCl vào dung dịch A cho đến khi kết tủa thu được hoàn toàn. Lọc lấy kết tủa X. Dung dịch còn lại là dung dịch B - Rửa kết tủa X bằng H2O rồi tác dụng tiếp với NH3 6M -Đun cách thủy đến nóng dung dịch B, thêm vào đó NH4Cl rắn, rồi thêm tiếp NH3 6M đến pH=9 thu được kết tủa Y - Cho kết tủa Y tác dụng với dung dịch NaOH 2M có một ít H2O2 Viết phương trình phản ứng hóa học xảy ra

Fill in the blank with the correct answer:

Cho n thuộc N* , n không chia hết cho 3, chứng tỏ n^2 chia 3 dư 1

Read the following passage circle the letter A, B, C, D on your answer sheet to indicate correct answer to each of the following questions. Most of us think that great ideas were the result of genius thinking. However, many of the greatest discoveries and inventions in history began with very simple beginnings. In the 18th century, James Watt was boiling water at home. As the water began to boil, he suddenly noticed that the steam was pushing the lid of the kettle. From this, he created the steam engine. In ancient Greece time, Archimedes stepped into a bathtub and felt that water was being pushed out when he stepped in. This is how he came up with the idea of how to find the purity of gold. In the 17th century, Isaac Newton was sitting under a tree when an apple fell and hit him on the head. This is when he realized the pulling force of the earth - the gravity. There are many other examples of how great ideas began with simple beginnings. What one needs to become an inventor are careful observation and a lot of hard work. Question 29. James Watt lived in ______. A. the 16th century B. the 17th century C. the 18th century D. the ancient Greece time Question 30. When did Archimedes come up with the idea of how to find purity gold? A. when he was boiling water B. when he was hit by an apple C. when he was being pushed out D. when he was stepping into the bath tub Question 31. What does the word “he” in bold refer to? A. James Watt B. Archimedes C. Isaac Newton D. an inventor Question 32. Which of the following is NOT true of inventors? A. They have simple thinkings. B. They have very careful observations. C. They work extremely hard. D. Their great ideas began with simple beginnings

Có 1 học sinh mỗi ngày giải ít nhất 1 bài tập , mỗi tuần giải không quá 12 bài tập . Chứng minh rằng có một số ngày liên tiếp học sinh đó giải đúng 20 bài tập

Vẽ góc bẹt xoy trên cùng 1 nửa mặt phẳng bờ là xy. Vẽ 2 tia om,on sao cho góc xom= 150, xon= 30. Tính mon.Vẽ tia op là tia đối của tia on. Tia oy có phải là tia phân giác mon ko? Vì sao?

JOB OPENING Club of a Foreign Mission in Islamabad seeks applications from qualified applicants to staff the position of a full time secretary for a General Accountant, with a starting salary of Rs. 17850 + 2050 Transport Allowance per month plus partial medical coverage plus other benefits. - Bachelor’s degree in Commerce or Accounting - Knowledge of computer, especially MS Office and MYOB - Excellent oral & written abilities in English - Be able to work under pressure - Possess good interpersonal skills, initiative, integrity, flexibility, adaptability, and must be a team player - At least 3 years of experience in the field of accounting Interested candidates send their applications along with CV, three passport photos to the Club Manager P.O Box 1042 Islamabad by close of business hour on Friday, 14 September, 2012 or email your CV’s at ccaccounts1@gmail.com. 1. (0.5 point) What position is being advertised? …………………………………………………………………………………………………… 2. (0.5 point) What are the job benefits offered by the company? …………………………………………………………………………………………………… 3. (0.5 point) What does an applicant need to provide? ……………………………………………………………………………………………………

Lm giúp mik nha mik đang cần gấp.

chứng tỏ phân số tối giản 2n+7/6n+23 với n thuộc N

Tính độ tan của AgBr trong nước nguyên chất ở 25 độ C. Biết E Ag+/Ag= 0,779V , E AgBr/Ag = 0,071V