Giúp mình ik
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10 If she is ill, she gets wet.
11 If she knew French, she could apply for the job.
12 Unless he washes his car, it will be dirty.
13 I am looking forward to writing a poem.
14 Because she was rich, she gave me money.
15 Though they are happy, they don't go out.
16 Though he didn't go out, despite the bad result.
17 I walked more slowly than him.
18 Lan is the most curious person in the class.
19 Ba is better than Hoa.
20 She has been planting trees for 20 days.
21 It is his first time baking a cake.
22 She has never published a book before.
23 A song is being sung by them.
24 Money has not been spent by anybody.
Who are you often meet on Saturday?
Why your father usually have beefsteak for his breakfast?
How many big beds in your bedroom?
Gọi n là hóa trị của kim loại R
n H2 = 2,8/22,4 = 0,125(mol)
2R + 2H2O → 2R(OH)n + nH2
Theo PTHH :
\(n_R = \dfrac{2}{n}n_{H_2} = \dfrac{0,25}{n}(mol)\\ \Rightarrow \dfrac{0,25}{n}.R =5,75\\ \Rightarrow R = 23n\)
Với n = 1 thì R = 23(Natri)