- #37 [phil.ng], 21-05-20 14:28
- #36 [羅有恆], 21-05-20 14:19初中應該有教盧瑟福散射實驗,用 alpha 粒子射穿金箔,發現原子唔係實心,入面完來係有好多空間,原子核相對好細粒。
- #35 [Drhandguns], 21-05-19 23:57#34
>>粒子唔會穿過 pass through 另一個粒子,他們在碰到面之前已經有巨大排斥力將佢嘅彈開。
我覺得寫呢句嘅人, 對particle嘅definition同我哋唔同。 以我哋嘅認知當然 atoms 或 molecules 係冇可能通過對方, 佢哋口中嘅model, 只係視水同酒精係兩個唔同size嘅實心spheres。 -
- #34 [羅有恆], 21-05-19 21:05初中講 particles 即係原子、份子嘅統稱啫。
樓主話『如何解釋 smaller particles pass through bigger particles
例如 : 當水和酒精混合, water particles 走進了 alcohol particles , 從而令到volume 沒改變.』
粒子唔會穿過 pass through 另一個粒子,他們在碰到面之前已經有巨大排斥力將佢嘅彈開。
粒子之間嘅距離係有空間嘅,唔係好似固體咁樣大家黐埋一齊震震吓。
所以當水和酒精混合,水份子同酒精份子共存,由純水空間同埋純酒精空間變成水-酒精混合空間,粒子間的平均距離唔同咗,所以就產生 50cc water + 50cc alcohol = 96cc 嘅情況。 - #33 [Drhandguns], 21-05-19 17:47勁, 我都諗到實會有人講fluid dynamics....
#30 初中生姐, 唔洗 quantum mechanics 同 fluid dynamics 掛!
我講嘅g, 係指實響地球做實驗時候嘅condition加大壓力standard溫度等。 - #32 [phil.ng], 21-05-19 16:23是
you mix 50 ml of water with 50 ml of ethanol,
非常清楚!50 十 50 是有變丶答案是 96
Again.....
If you mix 50 ml of water with 50 ml of ethanol, the total volume actual equals less than 100 ml. The reason the mixture does not add up to 100 ml is because the molecules that make up ethanol are smaller than the molecules that make up water. So, the ethanol molecules cram themselves between the water molecules. As a result, the volume is less than expected. The volume adds up to approximately 96 ml.
樓主是問
當水和酒精混合, water particles 走進了 alcohol particles , 從而令到volume 沒改變.
巳講明液態 及 volume 不變應是錯
其實不論氣或液丶都包含在"流體學"
最後修改時間: 2021-05-19 16:43:15 - #31 [敗家仔], 21-05-19 16:01係咪無講清楚個理論用響氣態同液態
50加50個例子係講緊個volume
質量無變,密度高左
最後修改時間: 2021-05-19 16:02:42 - #30 [羅有恆], 21-05-19 15:42#24 particles 之間主要嘅作用力唔係引力G,而係電力,最簡單可以用 Lennard-Jones potential 來 model。
- #29 [gary3886wong], 21-05-18 00:14啲小朋友學珠心算,會唔會對佢哋將來思考或者學習冇咁好?
- #28 [hahayanyan], 21-05-17 14:44hah if u need defined and specified answer......m, u need to define your question
"Space " in a sense of sizes......too........................
etc - #27 [daddykool], 21-05-17 14:20
- #26 [Drhandguns], 21-05-17 03:04你搞到我想食芝麻糊同腰果露.....
- #25 [phil.ng], 21-05-16 22:37不如又試下芝麻加腰果丶更大分別
沙糖加水
最後修改時間: 2021-05-16 22:40:54 - #24 [Drhandguns], 21-05-16 21:48#16 校友也!
其實要解釋非常之容易, 可以做一個非常簡單嘅實驗, 就係將兩樽同樣size嘅腰果同花生撈埋一齊, 睇下會唔會變成兩樽同之前一模一樣大小嘅果仁。 當你將依兩樽嘢到返落原本嘅觀度你會發覺少咗啲。 情況就等同將乙醇加水一樣。 Seeing is believing。
另外一樣解釋 small objects move pass large objects, 呢樣嘢嘅大前提係一定要有movement嘅kinetics 同 force, 響地球當然就係地心吸引力, 即係g。 用返上高mix咗嘅果仁, 如果你將佢哋chok下佢,擺抵一排, 你會發覺啲花生會沉曬底而腰果就喺面。 我相信你哋食過嗰啲日本口垃濕, 都會發覺啲大舊嘅嘢通常都喺個樽嘅面。 如果你喺太空做同一樣嘢嘅話就唔會發生。
講到外國同香港嘅syllabus, 外國著重用practical examples, 而香港嘅中學好鍾意你論化, 如果一啲學生喺立體思維比較差嘅話, 根本理解唔到, 唔係人人個腦都可以直接想像 H2O 同 C2H6OH 嘅size同形狀。 - #23 [phil.ng], 21-05-16 14:08鬼子佬實驗。50+50= 96
100+100=100 好大可能是錯
If you mix 50 ml of water with 50 ml of ethanol, the total volume actual equals less than 100 ml. The reason the mixture does not add up to 100 ml is because the molecules that make up ethanol are smaller than the molecules that make up water. So, the ethanol molecules cram themselves between the water molecules. As a result, the volume is less than expected. The volume adds up to approximately 96 ml.
最後修改時間: 2021-05-16 14:10:13 - #22 [phil.ng], 21-05-16 13:23https://www.thoughtco.com/miscibility-of-fluids-608180
If you add 50 mL of water to 50 mL of water you get 100 mL of water. Similarly, if you add 50 mL of ethanol (alcohol) to 50 mL of ethanol you get 100 mL of ethanol. But, if you mix 50 mL of water and 50 mL of ethanol you get approximately 96 mL of liquid, not 100 mL. Why?
The answer has to do with the different sizes of the water and ethanol molecules. Ethanol molecules are smaller than water molecules, so when the two liquids are mixed together the ethanol falls between the spaces left by the water. It's similar to what happens when you mix a liter of sand and a liter of rocks. You get less than two liters total volume because the sand fell between the rocks, right? Think of miscibility as "mixability" and it's easy to remember. Fluid volumes (liquids and gasses) aren't necessarily additive. Intermolecular forces (hydrogen bonding, London dispersion forces, dipole-dipole forces) also play their part in miscibility, but that's another story. - #21 [15--16], 21-05-16 13:09#1, water ⋯⋯alcohol⋯⋯volume⋯⋯:
100 ml water + 100 ml alcohol = 100 ml mixture ? - #20 [phil.ng], 21-05-16 12:17>>>若 no spaces between particles, particles 不是不能 move 嗎 ?
不同溫度丶movement 不同丶或停止 - #19 [phil.ng], 21-05-16 12:06>>>但是, 教科書說: smaller particles pass through bigger particles, 原因應不是二者的size大小不同吧.
應是smaller particles 能 pass through the spaces between bigger particles , 是嗎?
...................
小朋友角度丶將沙放入水丶沙經水落到底
反之先放沙丶水又會經沙落
留意不同壓力下丶反應不同
如水
What happens to water under high pressures without the possibility of escape? You can see that at high-pressure water assumes a solid form (ice): you will have ice X at 100 GPa, and what is labelled as hexagonal ice XI in the diagram but is actually superionic water or ice XVIII at 1 TPa (temperature range 0 to 650 K).
這就很難過!
最後修改時間: 2021-05-16 12:12:44 - #18 [phil.ng], 21-05-16 11:44>>>若 no spaces between particles, particles 不是不能 move 嗎 ?
簡單答丶Yes, but under infinite pressure
最後修改時間: 2021-05-16 11:45:20 - 下一頁 (1 of 2)
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一個吾小心就再垓爆!