Continue of Silver, nothing shiny here/ 此地無銀 。 續

In my last post Silver, nothing shiny here/ 此地無銀
I have mentioned that most activity related to silver are actually the result of silver ions, I have talked about silver ions can be added to antiperspirant to suppress bacterial growth.

There are more use of silver ions!!
Although there isn’t much people who still uses film to take photos, the old black and white film are made with silver(I) bromide. When sun light were exposed to the chemical on the film, it would release silver particles. Due to the small size of silver particles, it doesn't looks shiny, but instead, it looks black and dull.
儘管現在可能已經沒有什麽人會用菲林拍照， 在以前舊式的黑白照片是用溴化銀去做底片的。當陽光照射到底片的時候，就會釋放出銀粒子。由於粒子是非常非常細小，所以看上去並不是閃閃的，而是變得黑黑的。

This also reminds me of the new type of glasses which some people use recently, which is know as the photochromic lenses glasses. When you are indoor, the glasses looks like normal glasses, with transparent lens. But when you move outdoor or place with strong sunlight, the glasses will turn black within a couple minutes and looks like a sun glass and protect your eye. When you move back to indoor, the glasses will automatically turn back to transparent!
近年興起了一款叫全視線鏡片的眼鏡，簡單來説就是在室内還是正常的眼鏡, 透明鏡片，但走到室外有猛烈的陽光的時候，鏡片會自動轉黑，好像變成太陽眼鏡一樣，保護你的眼睛。然後當你走回室的時候，眼鏡又會自動變回透明鏡片！

The glasses make use of the properties of silver metal and silver ion. With the interconversion of this two states, one could achieve different transmittance. Under indoor condition, there is no strong sun light and it mostly exist as silver ion, so it have very high light transmittance. Yet, there is another reducing agent called copper(I) chloride, which would react with sun light and the silver ion will convert to silver metal under strong sun light condition. Again, due to the small silver particle size, just like the black and white photograph, it looks black and protect your eye.

實際上，這個眼鏡片就是用了銀和銀離子的特性，透過銀和銀離子的轉換而達至不同的透光率。在室内沒有強光的環境下，鏡片内主要以銀離子的方式呈現，所以有很高的透光率。在鏡片内還有另外一隻還原劑叫氯化亞銅，當你走到室外有強光的環境下，氯化亞銅會跟陽光反應，然後銀離子就會變成金屬銀的粒子。由於粒子細小，所以就跟黑白底片的原理一模一樣，看上去就是黑色的！

---

In my last post, I have also included the 1SBD lucky draw to whom that answer my question right and got drawn out.
在我的最後一篇文章中，我加入了1SBD抽獎活動,給答對我的問題的朋友。

My question was what was the serrated edge for on the coins?
我的問題是在硬幣上的邊緣,為什麼是要鋸齒形?

The answer is: To prevent people from filing down the coins for the shavings. In the past the coins were made with precious metals like silver and gold, so by filing down the coins edges, can actually profit from the tiny bits. So a serrated edge will result in a distinguishable difference if anyone attempts to file down the coins.
答案是：為了防止人們將硬幣的邊銼薄。在以前，硬幣是用貴金屬製成的，如金和銀，所以通過銼薄硬幣邊緣，實際上可以從微小的硬幣碎屑中獲利。因此，如果有人試圖將硬幣下銼薄，鋸齒狀邊緣將產生可區分的差異。

Due to some mistake issue, I decided to let anyone who leave comments answering my question the chance to draw.
由於一些錯誤的問題，我決定讓任何留言者回答我的問題都有抽獎機會。

Here are the ones that were entitled for the draw
這些是有機會抽的

and the lucky winner is: @redtea
幸運的獲獎者是：@redtea

Congratulation, and hope you guys learn something from the post~
恭喜,希望你們從文章中學到東西〜

photo source:

!

---

如果你喜歡我的帖子，請upvote並關注我 @biuiam
If you like my posts, please upvote and follow me @biuiam
Cheers~

---

SteemSTEM
其次，請考慮支持@steemstem項目。 SteemSTEM是一個社區驅動的項目，目的是促進Steemit的寫作/信息科學技術工程和數學發表。該項目不僅通過upvote和resteem STEM帖子，而且還將STEEM Power作為獎勵重新分配給Steemit不斷在科學/技術成長的社區成員。

要了解有關該項目的更多信息，請加入我們的steemit.chat（https://steemit.chat/channel/steemSTEM)， 我們一直在尋找幫跟我們理念相同 -- 追求提高STEM（和健康）帖子質量的人，在我們不斷增長的平台上發帖，所以我們很樂意聽到你的聲音！

最後可以考慮加入 @steemstem 投票軌跡，該項目賬戶只能對STEM相關帖子進行投票，因此作為投票軌跡的一部分，您可以選擇性地在我們不斷增長的科技社區在平台上受益。我們亦非常感謝你的支持。