圆柱的高不变，底面半径扩大到原来的3倍，它的侧面积扩大到原来的____，底面积扩大____倍。

同学们已经学习了同位素、同系物、同素异形体、同分异构体，你能区别这些概念吗？下面列出了几组物质，请将物质的合适组号填写在下表中。

① 和

② 和

③CH₄和CH₃CH₂CH₃；④金刚石与石墨；⑤氕、氘与氚；⑥¹⁶O、¹⁷O和¹⁸O；⑦乙醇(CH₃CH₂OH)和甲醚(CH₃OCH₃)；⑧氧气(O₂)与臭氧(O₃)。

类别	同位素	同系物	同素异形体	同分异构体
组号	____	____	____	____

对于某些离子的检验及结论中一定正确的是（   ）

阅读短文，判断下列句子是否正确。
    Ann went to Qingdao with her friends on her holiday. They went there by train. They went to the beautiful beach. The weather was sunny and hot. So they had great fun playing in the water.They ate lots of fresh fish for lunch. In the afternoon, they rode bikes. Jack fell off his bike and hurt his leg. So Jack stayed at the hotel and watched TV. On the second day, Ann took many pictures of the sea. And she bought some gifts for her parents. Anyway, they had a good time.

1g N₂中含有x个原子，则阿伏伽德罗常数是（   ）