Bài làm:

In my opinion, living in the countryside has its own pros and cons. According to benefits, it has fresh air, quite environment and friendly neighbors. Firstly, you have a healthy life. There are no dust, no smoke and no traffic jam. The air is fresh and the rain is also very clean. You can get raging water to cook rice and certainly have and tasted meal. Secondly, living in the countryside is peacful. It is very quiet to relax after working or there are many beautiful wide fields and fresh air.Finally, there are no separations in your town. Your neighors are friendly and helpful. They are really best friends. They will help you pleasently if you have trouble. Each problem has its solution anf your neighbors will share it for you. In conclusion, I prefer to live in the countryside, but I don't want to live there permanently.

In my opinion, living in the countryside has its own pros and cons. According to benefits, it has fresh air, quite environment and friendly neighbors. Firstly, you have a healthy life. There are no dust, no smoke and no traffic jam. The air is fresh and the rain is also very clean. You can get raging water to cook rice and certainly have and tasted meal. Secondly, living in the countryside is peacful. It is very quiet to relax after working or there are many beautiful wide fields and fresh air.Finally, there are no separations in your town. Your neighors are friendly and helpful. They are really best friends. They will help you pleasently if you have trouble. Each problem has its solution anf your neighbors will share it for you. In conclusion, I prefer to live in the countryside, but I don't want to live there permanently.

Trước khi cho thì Hồng nhiều hơn Lan số con tem là:

                            5 + 1 = 6 (con tem )

                                                     Đáp số : 6 con tem

In my opinion, living in the countryside has its own pros and cons. According to benefits, it has fresh air, quite environment and friendly neighbors. Firstly, you have a healthy life. There are no dust, no smoke and no traffic jam. The air is fresh and the rain is also very clean. You can get raging water to cook rice and certainly have and tasted meal. Secondly, living in the countryside is peacful. It is very quiet to relax after working or there are many beautiful wide fields and fresh air.Finally, there are no separations in your town. Your neighors are friendly and helpful. They are really best friends. They will help you pleasently if you have trouble. Each problem has its solution anf your neighbors will share it for you. In conclusion, I prefer to live in the countryside, but I don't want to live there permanently.

a) PTHH: 4Na+O₂=> 2Na₂O

Số nt Na: số pt O₂: số pt Na₂O=4:1

Số nt Na: số pt Na₂O=4:2=2

Số pt O₂ :số pt Na₂O

b) PTHH: P₂O₅+3H₂O=>2H₃PO₄

Số pt P₂O₅: số pt H₂O = 1:3

Số pt H₂O:số pt H₂PO₄ = 3:2

Số P₂O₅:số pt H₃PO₄ = 1:2

Bài t vừa lt vừa lm xong cho cn Phương ấy:>>

a) PTHH: CaCO₃ -> CaO+CO₂

b) Theo ĐLBTKL ta có:

m_CaO +m_CO2=m_CaCO3

=> m_^CaO=m_CaCO3- m_CO2

hay mCaO=5-1,98

=>mCaO=3,02(g)

Vậy khối lượng vôi sống thu được là 3,02 g

c) Theo ĐLBTKL ta có:

m_CaO+m_CO2=m_CaCO3

Mà m_CaCO3=4,5 tấn

Dư 0,5 tấn

=> m_CaCO3 sau phản ứng là 4 tấn

Hiệu suất phản ứng là:

\(\dfrac{mCaCO3}{mCaO+mCO2}.100=\dfrac{4}{4,5}.100=88,9\%\)

Vậy nếu sau phản ứng còn dư 0,5 tấn CaCO3 thì hiệu suất phản ứng đã đạt 88,9%

Năm 2013 số sách trong thư viện tăng lên số cuốn là:10 000:100x10=1000(cuon)

Năm 2013 trong thư viện có số cuốn sách là:10000+1000=11000(cuon)

tick nha

KHHH là I

Theo bào ta có: \(\dfrac{1}{5}X=\dfrac{1}{4}Cu\)

\(\Rightarrow\dfrac{1}{5}X=\dfrac{1}{4}.64\\ \Rightarrow\dfrac{1}{5}X=16\\ \Rightarrow X=80\)

=> X là Brom(Br)

Vậy X là Brom (Br)