计算在标准状态下氢气分子的平均自由程和平均碰撞频率。（氢分子的有效直径d=2x10^-10m)

A . ['https://assets.asklib.com/psource/2016071711541072263.jpg 与T无关B .https://assets.asklib.com/psource/2016071711541072263.jpg 与成https://assets.asklib.com/psource/2016071711541520252.jpg 正比C . 与https://assets.asklib.com/psource/2016071711541520252.jpg 成反比D .https://assets.asklib.com/psource/2016071711541072263.jpg 与T成反比

A . ['https://assets.asklib.com/psource/2016071713152316030.jpg 和https://assets.asklib.com/psource/2016071713152742735.jpg 都增大B .https://assets.asklib.com/psource/2016071713152316030.jpg 和https://assets.asklib.com/psource/2016071713152742735.jpg 都减小C .https://assets.asklib.com/psource/2016071713152742735.jpg 减小而https://assets.asklib.com/psource/2016071713152316030.jpg 增大D .https://assets.asklib.com/psource/2016071713152742735.jpg 增大而https://assets.asklib.com/psource/2016071713152316030.jpg 减小

A . 1 B . 2 C . 3 D . 4

A .https://assets.asklib.com/images/image2/2017051110385098774.jpg 和https://assets.asklib.com/images/image2/2017051110380742552.jpg 都增大B . 和https://assets.asklib.com/images/image2/2017051110385098774.jpg https://assets.asklib.com/images/image2/2017051110380742552.jpg 都减小C .https://assets.asklib.com/images/image2/2017051110385098774.jpg 减小而https://assets.asklib.com/images/image2/2017051110380742552.jpg 增大D .https://assets.asklib.com/images/image2/2017051110385098774.jpg 增大而https://assets.asklib.com/images/image2/2017051110380742552.jpg 减小

A . 增大压强，提高温度 B . 增大压强，降低温度 C . 降低压强，提高温度 D . 降低压强，温度保持不变

A . ['https://assets.asklib.com/psource/2015110116090848342.png 和https://assets.asklib.com/psource/201511011609344439.png 都增大1倍B .https://assets.asklib.com/psource/2015110116090848342.png 和https://assets.asklib.com/psource/201511011609344439.png 都减为原来的一半C .https://assets.asklib.com/psource/2015110116090848342.png 增大1倍而https://assets.asklib.com/psource/201511011609344439.png 减为原来的一半D .https://assets.asklib.com/psource/2015110116090848342.png 减为原来的一半https://assets.asklib.com/psource/201511011609344439.png 而增大1倍

A . 增大，不变 B . 不变，增大 C . 和都增大 D . 和都不变

A . ['https://assets.asklib.com/psource/2015110115233384776.png 和https://assets.asklib.com/psource/2015110115233384776.png 1都相等B .https://assets.asklib.com/psource/2015110115233384776.png 相等而https://assets.asklib.com/psource/2015110115233384776.png 1不相等C .https://assets.asklib.com/psource/2015110115233384776.png 1相等https://assets.asklib.com/psource/2015110115233384776.png 而不相等D .https://assets.asklib.com/psource/2015110115233384776.png 和https://assets.asklib.com/psource/2015110115233384776.png 1都不相等

A . ['https://assets.asklib.com/psource/2015102709053931679.jpg 和https://assets.asklib.com/psource/2015102709054145245.jpg 都增大一倍B .https://assets.asklib.com/psource/2015102709053931679.jpg 和https://assets.asklib.com/psource/2015102709054145245.jpg 都减为原来的一半C .https://assets.asklib.com/psource/2015102709053931679.jpg 增大一倍而https://assets.asklib.com/psource/2015102709054145245.jpg 减为原来的一半D .https://assets.asklib.com/psource/2015102709053931679.jpg 减为原来的一半而https://assets.asklib.com/psource/2015102709054145245.jpg 增大一倍

A .https://assets.asklib.com/images/image2/2017051115145513283.jpg 增大，https://assets.asklib.com/images/image2/2017051115140643714.jpg 不变B .https://assets.asklib.com/images/image2/2017051115145513283.jpg 不变，https://assets.asklib.com/images/image2/2017051115140643714.jpg 增大C .https://assets.asklib.com/images/image2/2017051115145513283.jpg 和都https://assets.asklib.com/images/image2/2017051115140643714.jpg 增大D .https://assets.asklib.com/images/image2/2017051115145513283.jpg 和都https://assets.asklib.com/images/image2/2017051115140643714.jpg 不变

A . 减小而不变 B . 减小而增大 C . 增大而减小 D . 不变而增大

A . ['https://assets.asklib.com/psource/2016071617503110747.jpg 和https://assets.asklib.com/psource/2016071617503484027.jpg 都相等B .https://assets.asklib.com/psource/2016071617503110747.jpg 相等而https://assets.asklib.com/psource/2016071617503484027.jpg 不相等C . 相https://assets.asklib.com/psource/2016071617503484027.jpg 等而https://assets.asklib.com/psource/2016071617503110747.jpg 不相等D .https://assets.asklib.com/psource/2016071617503110747.jpg 和https://assets.asklib.com/psource/2016071617503484027.jpg 都不相等

A . 增大，但不变 B . 不变，但增大 C . 和都增大 D . 和都不变

A . ['https://assets.asklib.com/psource/2016071713390535263.jpg 和https://assets.asklib.com/psource/2016071713390918762.jpg 都增大1倍B .https://assets.asklib.com/psource/2016071713390535263.jpg 和https://assets.asklib.com/psource/2016071713390918762.jpg 都减为原来的一半C .https://assets.asklib.com/psource/2016071713390535263.jpg 增大1倍而https://assets.asklib.com/psource/2016071713390918762.jpg 减为原来的一半D .https://assets.asklib.com/psource/2016071713390535263.jpg 减小为原来的一半而https://assets.asklib.com/psource/2016071713390918762.jpg 增大1倍

某种理想气体在温度为300 K时，分子平均碰撞频率为<img src='https://img2.soutiyun.com/ask/2020-05-11/958046073357017.png' />=6. 0×109/s.若保持压强不变，当温度升到800K时,求分子的平均碰撞频率<img src='https://img2.soutiyun.com/ask/2020-05-11/958046085885324.png' />.

在一个标准大气压下,氮气分子的平均自由程为6.0×10-8m,而目前实验室能够获得的极限真空约为<img src='https://img2.soutiyun.com/ask/2020-05-11/958045652421033.png' />. (1)当温度不变时,在该极限真空条件下,氮气分子的平均自由程为多少？ (2)若温度T= 27℃ ,在两种大气压强条件下,氮气分子的密度各为多少？

A．与T无关 B．与成正比 C．与成反比 D．与成正比