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Hi there!
大家好!
Squeaks and I were just talking about one of our favorite summer foods: Fruit salad!
我和吱吱剛剛在談論我們最喜歡的夏季食物之一:水果沙拉!
Making a fruit salad is just a matter of taking pieces of fruitand mixing them all up in a bowl.
做水果沙拉就是把水果塊放在碗里攪拌。
What can be hard is deciding what yummy fruits to include!
最難的是決定要放哪些美味的水果!
What would you like to add, Squeaks?
吱吱，你想要放那些水果?
Ooh, good choices.
哦,不錯的選擇。
Squeaks would make sure he had cherries and watermelon, while I’d pick…
吱吱確認他要櫻桃和西瓜，而我則會選擇……
Hmm, let’s see, pineapple and blueberries!
嗯，讓我看看，菠蘿和藍莓!
Blueberries are my favorite parts of a fruit salad.
藍莓是水果沙拉中我最喜歡的。
In fact, sometimes I eat all of the other fruit first, and save the blueberries for last.
事實上，有時我會先吃掉所有水果，把藍莓留到最后。
It’s not really that hard to do, because the pieces that make up a fruit salad mixture are still there.
其實做起來并沒有那么難，因為組成水果沙拉的各個部分仍然沒變。
Mixing them together doesn’t change them!
把各種水果混合在一起并不會改變它們!
But sometimes, mixing two things together results in what’s called a chemical change.
但有時，兩種物質混合在一起會導致所謂的化學變化。
During a chemical change, the things that get mixed together become something new!
在化學變化中，混合在一起的東西會變成新的東西!
So we can’t pull them apart very easily, like we can with the mixture of fruit in our fruit salad.
我們把它們分開不是很容易，就像我們在水果沙拉里混合水果一樣。
Sure we can try to make a chemical change happen!
當然，我們可以嘗試讓化學變化發生!
This experiment will be super fun, and very messy, so it’s a good thing we’re outside.
這個實驗會非常有趣，也會搞得亂糟糟，所以幸好我們在外面。
We’re going to make something that looks a lot like toothpaste…
我們要做一些看起來很像牙膏的東西……
and I think there’s going to be a lot of it — so much that an elephant could brush its teeth!
而且我認為會有很多——多到大象都能刷牙了!
Now, if you’re going to try this at home, it’s really important that you do this safely.
現在，如果你要在家里做這個實驗，確保安全是非常重要的。
That means you need help from an adult, and some safety glasses or goggles.
這意味著你需要家長的幫助，以及一些安全眼鏡或護目鏡。
For this experiment we’re going to need an empty plastic bottle, a funnel, a measuring cup and spoon, some dry yeast, warm water, food coloring, and some liquid dish soap.
做這個實驗，我們需要一個空的塑料瓶，一個漏斗，一個量杯和勺子，一些干酵母，溫水，食用色素和一些洗潔精。
Finally, we’ll need something called hydrogen peroxide.
最后，我們需要一種叫過氧化氫的東西。
That’s right!
正確!
Sometimes adults will use hydrogen peroxide to kill germs, so you might have some at home.
有時成年人會使用過氧化氫來消殺細菌，所以你家里可能有一些。
Oh! And you might also want to do this experiment on a large tray or in a large tub.
噢!你可能還想在一個大托盤或大浴缸中做這個實驗。
Ohh, you’ll see why, Squeaks!
哦，吱吱，你會知道為什么的!
Now, let’s get started.
現在，我們開始吧。
First thing — safety first!
第一件事——安全第一!
Glasses… on!
戴上眼鏡!
Next, we’ll mix our yeast and warm water together and wait for at least 30 seconds.
接下來，我們將酵母和溫水混合在一起，等待至少30秒。
It’s okay to wait a little longer, though, so let’s get the other part of the experiment ready.
不過，再等一段時間也沒關系，所以讓我們準備好實驗的另一部分吧。
We’ll pour our hydrogen peroxide into the bottle using the funnel.
我們用漏斗把過氧化氫倒入瓶子里。
Next, we’ll add a few squirts of dish soap.
接下來，加幾滴洗潔精。
And swirl the bottle so that everything mixes together.
旋轉瓶子，讓所有東西混合在一起。
Let’s check on our yeast.
讓我們檢查一下酵母。
Oh, look at our yeast mixture, Squeaks!
哦，吱吱，看看我們的酵母混合物!
What do you see?
你看到了什么?
Ooh, I do too!
哦，我也是!
The yeast and water mixture is kind of bubbly.
酵母和水的混合物有點起泡了。
I agree!
我同意!
While it is bubbly, it doesn’t look like toothpaste, and there’s not a lot of it.
雖然起氣泡了，但看起來不像牙膏，而且牙膏的用量也不多。
And if we look at the bottle, we can see there’s nothing in there that looks like toothpaste, either.
如果我們看看這個瓶子，我們可以看到里面也沒有什么看起來像牙膏的東西。
But I think we’re ready for our chemical change to happen!
但我認為我們已經準備好發生化學變化了!
We’ll quickly pour the yeast mixture into the bottle on the count of three.
數到三，我們迅速將酵母混合物倒入瓶中。
Ready?
準備好了嗎?
One…Two…THREE!
一……二……三!
Oh, and look at all the foam!
哦，看看這些泡沫!
There’s SO MUCH of it!
有這么多!
What else do you notice about it?
你還注意到了什么?
Do you think it looks at all like what we started with?
你覺得它看起來像我們開始的時候嗎?
Me neither!
我也不!
And look, there’s no way we could pick what we started with out of this mixture.
看，我們不可能從混合物中選擇我們開始時放的物質。
Do you notice anything else?
你還注意到別的嗎?
Ooh, yes!
哦,是的!
The bottle feels warm.
這個瓶子摸起來是熱的。
And that warmth is a clue that a chemical reaction took place!
這種溫度變化是發生化學反應的線索!
Some chemical reactions, like this one, release heat.
一些化學反應，比如這個，會釋放熱量。
And bubbles are also often a way to tell that a chemical reaction took place.
而氣泡通常也是一種表明發生了化學反應的方式。
If we look closely at the foam, we can see that it’s made of TONS of tiny bubbles!
如果我們仔細觀察泡沫，我們會發現它是由無數的小氣泡組成的!
Another clue.
另一個線索。
So I’d say that we definitely had a chemical change take place in our experiment.
我想說我們的實驗中肯定發生了化學變化。
We’ll leave our goggles on until we’re done getting cleaned up, Squeaks.
吱吱，在我們清理完之前，我們會一直戴著護目鏡。
Then we can talk about what happened!
然后我們再談談發生了什么!
Let’s start by looking at what we started with:
讓我們先看看我們開始時放的東西:
We had yeast, water, dish soap, food coloring, and hydrogen peroxide.
我們放了酵母、水、洗潔精、食用色素和過氧化氫。
And what we have now doesn’t look like any of those things.
而我們現在所擁有的一切與原來的這些都不一樣。
A chemical change happened, so we can’t go back to what we started with!
發生了化學變化，所以我們無法回到開始的時候!
But some changes can be reversed.
但有些變化是可以逆轉的。
If you put some water in the freezer, after a while it will freeze into solid ice.
如果你在冰箱里放一些水，過一會兒它就會凍成固態的冰。
And if you take that ice out and put it in the sun or on the counter for a little while, it will melt into liquid water again.
如果你把冰拿出來，放在太陽下或柜臺上一會兒，它會再次融化成液態水。
So, you get back what you started with!
所以，你得到了最開始的東西!
But our chemical change isn’t reversible like that.
但是這個化學變化不是可逆的。
Our toothpaste won’t go back to being soap and yeast and everything else.
我們的牙膏不會再變成肥皂、酵母和其他東西了。
Can you think of any other changes that aren’t reversible?
你還能想到其他不可逆的變化嗎?
Oh, yeah!
哦,耶!
When you heat up an egg, it goes from runny and gooey, to cooked and yummy.
當你加熱雞蛋時，它就會從流動粘稠的液體變成煮熟的美味。
But even if you don’t finish your breakfast and leave the egg out for a while, it stays cooked.
但即使你沒有吃完早餐，把雞蛋放在外面一段時間，它也會一直是煮好的狀態。
The change wasn’t reversible.
這種變化是不可逆轉的。
But speaking of yummy things, remember that fruit salad mixture we were talking about?
但說到美味，還記得我們之前說過的水果沙拉混合物嗎?
I’d sure love some of that now.
我現在肯定很喜歡。
So let’s go and make some!
所以讓我們去做一些吧!
Thanks for joining us here at The Fort!
感謝您觀看我們在福特堡的節目!
If you want to keep learning and having fun with me, Squeaks, Mr. Brown, and all our other friends, be sure to hit the subscribe button, and we'll see you next time on SciShow Kids!
如果你想繼續與我、吱吱、布朗先生以及我們所有的朋友一起學習、一起玩耍，一定要點擊訂閱按鈕，我們下次《少兒科學秀》再見!
