Activa JavaScript para disfrutar de los vídeos de la Mediateca.
Science Experiment
Ajuste de pantallaEl ajuste de pantalla se aprecia al ver el vídeo en pantalla completa. Elige la presentación que más te guste:
Hi, I'm Matthew. Today on Experiment Time, we're going to compare oxidation in different fruits.
00:00:00
Have you ever noticed a fruit that's turned brown? Or have you ever made a fruit salad and seen what
00:00:26
happens to the fruit after you slice it? Hmm, what's happening? We're going to compare different
00:00:33
fruits I've chosen an apple an orange a banana and also an avocado we also need
00:00:41
a plate for each fruit and a knife cut fruit turns brown because of oxidation
00:00:57
when the soft interior part of the fruit is exposed to air its electrons are lost
00:01:07
The oxygen in the air gains electrons from the fruits atoms. This is a chemical
00:01:13
change. But which fruit do you think will oxidize the most? Which fruit will
00:01:21
oxidize the least? Think about it and then write a hypothesis. Now we cut the
00:01:27
fruit in half carefully with the knife. Now we put each fruit on a plate and
00:01:35
observe it carefully wait 10 minutes do this three times so you can see the
00:01:52
oxidation process develop while you're waiting you can draw a results table the
00:02:04
banana has started to go brown and the Apple as well the avocado still looks
00:02:15
fresh. And the orange? The orange is still fresh as well. Write down what you
00:02:24
reserve in the table. If you have a camera you can use it to take photos at
00:02:33
each stage. Now let's wait ten more minutes. We can see the fruits are still
00:02:41
oxidizing. The banana and the apple are darker than before. The avocado is
00:02:59
starting to turn brown around the edges and the orange still hasn't changed record your results
00:03:07
on a table and take a photo right so half an hour has passed since we cut the fruit
00:03:14
i can certainly see the difference when you have recorded your results you can start to analyze
00:03:25
them what changes in appearance do you observe how long did it take each fruit to change
00:03:31
Which fruits didn't change at all? Was your hypothesis correct? Why do you think the orange
00:03:42
didn't go brown like the other fruits? That's right, it's a citrus fruit and the citric acid
00:03:51
slows down the oxidation process. How can you use this information to help you preserve fruit?
00:03:59
That's right, squeeze a bit of orange juice or lemon juice on your sliced fruits and they won't go brown
00:04:08
Great, you try, choose your own fruits
00:04:17
See you later alligator
00:04:22
- Idioma/s:
- Autor/es:
- Oxford Education
- Subido por:
- Fernando Luis R.
- Licencia:
- Todos los derechos reservados
- Visualizaciones:
- 122
- Fecha:
- 17 de marzo de 2020 - 14:51
- Visibilidad:
- Público
- Centro:
- CP INF-PRI CALDERON DE LA BARCA
- Duración:
- 04′ 30″
- Relación de aspecto:
- 1.78:1
- Resolución:
- 854x480 píxeles
- Tamaño:
- 68.57 MBytes
