用“>”、“<”或“=”填写下列空格:
(1)沸点:H2S ____H2O
(2)酸性:H2SO4 ____H2SeO4
(3)原子的核外电子排布中,未成对电子数:24Cr ____25Mn
(4)A元素的电子构型为ns2np3,B元素的电子构型为ns2np4,第一电离能:A ____B.
如图为用分光光度计测定叶片中两类色素吸收不同波长光波的曲线图,请判定A和B分别为何种色素( )
连线题。
①What did you do last weekend? ____ A. I am singing and dancing.
②What are you doing? ____ B. It was great.
③Did Amy cook this morning? ____ C. I washed my clothes.
④Do you like sports? ____ D. No, she didn't.
⑤How was your weekend? ____ E. Yes, I do.
x
π6
7π6
ωx+φ
0
π2
π
3π2
2π
Asin(ωx+φ)
2
﹣2