Tổng số hạt trong $Y$ là $13$
$\to 2p+n=13$
$\to n=13-2p$
Ta có: $p\le 13-2p\le 1,5p$
$\to \dfrac{13}{2+1,5}\le p\le \dfrac{13}{2+1}$
$\to 3,7\le p\le 4,3$
$\to p=4$
$\to 13-2.4=5$
Suy ra nguyên tử $Y$ có $4p, 4e, 5n$
Khối lượng nguyên tử:
$4.1,67.10^{-24}+4.9,1.10^{-28}+5.1,67.10^{-24}=1,503364.10^{-23}g$
Em tham khảo nha :
\(\begin{array}{l}\text{Tổng số hạt của nguyên tử Y là 13}\\2{p_Y} + {n_Y} = 13 \Rightarrow {n_Y} = 13 - 2{p_Y}\\1 \le \dfrac{{{n_Y}}}{{{p_Y}}} \le 1,5 \Rightarrow 1 \le \dfrac{{13 - 2{p_Y}}}{{{p_Y}}} \le 1,5\\ \Rightarrow 3,7 \le {p_Y} \le 4,33\\ \Rightarrow {p_Y} = {e_Y} = 4\\{n_Y} = 13 - 8 = 5\\{m_Y} = 4 \times 1,6726 \times {10^{ - 24}} + 4 \times 9,1094 \times {10^{ - 28}} + 5 \times 1,6748 \times {10^{ - 24}}\\{m_Y} = 1,507 \times {10^{ - 23}}g\end{array}\)
Giúp em trắc ngh vs ạ av em cảm mơn
Bài 8: So sánh: d, $8^{5}$ và $3.4^{7}$ $.8^{5}$ Bài 11: Tính giá trị biểu thức sau: A = 2^30 . 5^7 + 2^13 . 5^27 / 2^27 . 5^7 + 2^10 . 5^27
giúp mình bài này vỡi cần gấp cảm ơn các bn
Ai lm hộ tui ạ Hahahhahahhahahah
1. The keepers feed the lions at 3 pm every day. The lions ________________________________________________. 2. They say that Nam is the brightest student in our school. No other _____________________________________________________. 3. I would prefer you to deliver the sofa on Friday. I would rather_____________________________________________. 4. The bridge was so low that the bus couldn't go under it. It was ___________________________________________________. 5. That was a silly thing to say. What ___________________________________________________. 6. We've run out of tea. There ___________________________________________________. 7. I last saw him when I was a student. I haven't ________________________________________________. 8. Susan was too excited to sleep. Susan was ______________________________________________. 9. Robert has not had a job for two years. Robert has been _________________________________________. 10. They haven’t played tennis for almost two years. They stopped _____________________________________.
Ghi cấu trúc thì present sinple và present continuous.
giúp mình đề thử văn này vs mọi nh
Cách để thuộc công thức về câu xác định và câu không xác định
Một hộp gồm 10 viên bi trắng, 8 viên bi đỏ và 6 viên bi xanh. Chọn ngẫu nhiên 3 viên bi. Tính xác suất để thu được. a. 3 viên bi cùng màu b. 3 viên bi khác màu c. Ít nhất một viên bị trắng
Ex 2 : Choose personal pronouns or object pronouns : Chọn ĐTNX hay ĐTTN 1. (Him, He) and Frank caught the most fish. 2. Carlo looked for Larry and (her, she) was at the party. 3. You and (me, I) had better go. 4. Grace invited both Betsy and (me, I). 5. The Kaplans and (us, we) are going in our car. 6. The waitress brought Glen and (me, I) the wrong orders. 7. Mr. Voss drives Tim and (her, she) to school on Mondays. 8. Why don’t you sit between (her, she) and (me, I). 9. The books belong to (them, they) and (us, we). 10. The man asked (her, she) and David several questions after the program. 11. Mrs. Neilsen was worried about you and (them, they). 12. Between you and (me, I), we think he’s a fraud. 13. Neither (them, they) nor (us, we) were ready at six. 14. Do you blame Spence and (me, I) for leaving? 15. Either (her, she) or (him, he) broke a record. 16. (We/us) all went with (them/they). 17. They know all about my friends and (I/me). 18. His mother and (he/him) came last night. 19. There are some letters for you and (me/I). 20. What would you do if you were (he/ him)
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