This is my day
I am a doctor. I work at night. I go to work at 6:30 p. m. I eat dinner at 9:30. I usually go home at 8:00 in the morning. After breakfast, I go to bed at 9:10 a. m. I usually get up at 2:30 in the afternoon. I eat lunch at 3:00 in the afternoon. Then I play sports at 4:00 in the afternoon.
This is my day. I enjoy my life.
电热器是利用电流的____ 制成的加热设备,电热器的发热体是由电阻率____ (选填“大”或“小”)的合金丝绕在绝缘材料上制成的,某电热器的电阻为220Ω,工作时通过的电流为1A,则该电热器1min发热____ J.(注:长1m、横截面积1mm的导体在20℃时的电阻值称为这种导体的电阻率)
科技馆是社会大课堂实践活动的重要基地,其中“物质之妙”展区蕴含着丰富的化学知识.请回答题.
A为展区中展示的金刚石的微观结构模型,构成金刚石的基本微粒是____ .
B介绍了14C测年法,14C是质子数为6,中子数为8的碳原子,该原子中核外电子数为____ .
C介绍了化学家门捷列夫,其在化学史上的突出贡献是____ (填数字序号).
①提出分子学说 ②编制元素周期表 ③提出近代原子学说.