What do you do this time yesterday ?

1.

Có \(M_{2O_2}=2.\left(16.2\right)=2.32=64g/mol\)

Có \(M_{N_2}=14.2=28g/mol\)

Tỉ lệ \(\frac{d_{2O_2}}{d_{N_2}}=\frac{M_{2O_2}}{M_{N_2}}=\frac{64}{28}=2,3\)

Mà \(2,3>1\)

Vậy \(2O_2\) nặng hơn \(N_2\) là 2,3 lần

2.

Có \(M_{5Al}=5.27=135g/mol\)

\(M_{Fe}=56.2=112g/mol\)

Tỉ lệ \(\frac{d_{5Al}}{d_{2Fe}}=\frac{M_{5Al}}{M_{2Fe}}=135=1,2\)

Mà \(1,2>1\)

Vậy 5Al nặng hơn 2Fe là 1,2 lần

dgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgx

h2 = 2 hidro , ==> h2 + v2 = 1*2 + v2

dgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgx

Đặt hoá trị của M là x

Theo quy tắc hoá trị, có \(x.1=I.3\rightarrow x=III\)

Vậy CTHH của Oxit kim loại M là \(M_2O_3\)

Có \(NTK_M.2+NTK_O.3=102\)

\(\rightarrow NTK_M.2+16.3=102\)

\(\rightarrow NTK_M=\frac{102-16.3}{2}==27đvC\)

The biggest supercluster known in the universe is the Hercules-Corona Borealis Great Wall.

TL

The biggest supercluster known in the universe is the Hercules-Corona Borealis Great Wall. It was first reported in 2013 and has been studied several times. It's so big that light takes about 10 billion years to move across the structure. For perspective, the universe is only 13.8 billion years old.

Hok tốt

#Kirito

ko nha bạn

7đ nha bạn 

Èo, may rủi  :)))

@Cỏ

#Forever