用天平和量筒测量盐水的密度: (1)在使用托盘天平前要对天平进行调节.按正确的顺

题型:问答题

问题:

用天平和量筒测量盐水的密度:

(1)在使用托盘天平前要对天平进行调节.按正确的顺序将下列各步骤前的字母排列______.

A.组装好天平,把天平放在水平台面上.

B.调节天平的平衡螺母,使天平横梁水平平.

C.把游码置于标尺的零刻线处.

(2)实验所依据的公式是______.

(3)实验过程:

a.在玻璃杯中盛上盐水,放在调节好的天平左盘上称量,当天平重新平衡时,读出砝码和游码的读数为124.2g.(已填入表中)

b.把玻璃杯中的盐水倒入量筒中一部分,如图,记下量筒中盐水的体积并填入表中.

c.把玻璃杯和剩余盐水放在天平左盘上称量,当天平重新平衡时,所用砝码和游码位置如图所示,将玻璃杯和剩余盐水的质量填入表中.

d.计算出盐水的质量和密度,填入表中.

玻璃杯和盐水的质量m1/g玻璃杯和剩余盐水的质量m2/g量筒中盐水的质量m/g量筒中盐水的体积V/cm3盐水的密度

ρ/(g/m3

124.2________________________

考点:液体密度的测量
题型:问答题

一个物体也没有,有0表示.0也是自然数.______.(判断对错)

题型:问答题

Questions 6 to 10 are based on the following passage: (10 分)In previous generations, young people were under their parents’ control; now the teenagechildren of the West’s richest generation were ready for something to get excited about. The Beatlessimply put a spark to a fuse (导火线) that was waiting to be lit.Everything changed, and what changed for the Beatles was their lives and their working habits,in the midst of the hysterical (歇斯底里的)following the band attracted.. Because of the demand ofthe fans to see them perform, they played bigger and bigger venues (meeting places), especially inAmerica.But John, Paul, George and Ringo became increasingly unhappy that, because of the screamingof their fans, neither the band nor the audience could hear the music. Creatively frustrated and tiredof the pressures of life under siege (围攻) from their fans, they retired from playing concerts in 1966and decided to concentrate on recording.It was from this point that the brilliance of the Beades really began to reveal itself: they wouldrecord over their career some 200 songs. Never before nor since has any recording and writing groupeven developed and yet remained the same in the way the Beades did. Their songs never lost their universal appeal thanks to the warmth and timelessness of theirmelodies and lyrics.John and Paul were powerful singers with distinctive styles. It became apparent that, despite thefact that the songwriting credits were always equally attributed to them, Paul and John wrote andsang their own songs. George also contributed two or three of his own compositions to each of theBeatles eleven albums. Even Ringo wrote and sang the occasional song.

What can we learn about the Beafles’ music

A.It was a fine examPle of music for simple singalong songs.

B.Its appeal was not limited to any particular time or group of people.

C.It was simple in form but rich in meaning.

D.It reached a height which other pop music groups had never reached for their lyrics and melodies.

题型:问答题

以下是免疫病理检查适应证的有()

A.大疱性皮肤病

B.银屑病

C.特应性皮炎

D.结节性痒疹

题型:问答题

晶态固体中扩散的微观机制有 (11) (12) (13) (14)

题型:问答题

感受颜色和强光的细胞是().

A.视锥细胞

B.视杆细胞

C.双极细胞

D.节细胞

更多题库