1 00:00:00,000 --> 00:00:09,000 Hello everyone, this is a video in which we are going to continue with the Unit 5 of Natural Science. 2 00:00:09,580 --> 00:00:14,720 So let's gonna start checking what we learned in the previous unit. 3 00:00:15,519 --> 00:00:18,000 So I'm just gonna read it for you. 4 00:00:18,760 --> 00:00:21,480 Sorry, in the previous unit, no, in the previous part of the topic. 5 00:00:22,219 --> 00:00:26,039 So we learned about light. 6 00:00:26,920 --> 00:00:32,759 And we learned that light is a form of energy that lets us see objects. 7 00:00:32,759 --> 00:00:38,579 So, thanks to light we can observe their size, shape and color. 8 00:00:39,420 --> 00:00:47,340 So, here we continue and we discover that we have two different types of light sources, 9 00:00:47,780 --> 00:00:50,500 which are the natural one and the artificial one. 10 00:00:50,780 --> 00:00:55,560 The natural one came from natural sources, of course, 11 00:00:55,560 --> 00:00:58,200 examples, the sun 12 00:00:58,200 --> 00:00:59,240 or the lightning 13 00:00:59,240 --> 00:01:02,659 los rayos, los relámpagos 14 00:01:02,659 --> 00:01:04,099 right? light 15 00:01:04,099 --> 00:01:06,060 can also come from artificial 16 00:01:06,060 --> 00:01:08,319 sources such as light bulbs 17 00:01:08,319 --> 00:01:10,500 and wax candles, las velas 18 00:01:10,500 --> 00:01:11,099 right? 19 00:01:13,670 --> 00:01:16,090 talking about the properties of light 20 00:01:16,090 --> 00:01:17,989 of the characteristics of 21 00:01:17,989 --> 00:01:19,950 light, we have to mention 22 00:01:19,950 --> 00:01:22,069 three aspects, the first one 23 00:01:22,069 --> 00:01:24,250 is the speed, since light 24 00:01:24,250 --> 00:01:26,069 travels very quickly, right? 25 00:01:26,069 --> 00:01:30,049 is the fastest form of energy in the universe, right? 26 00:01:30,189 --> 00:01:31,189 La velocidad de la luz. 27 00:01:31,969 --> 00:01:35,670 Color, while white light is not really white. 28 00:01:36,150 --> 00:01:41,290 No, color has, light has seven colors, 29 00:01:41,530 --> 00:01:44,370 the ones that we can find in the rainbow. 30 00:01:44,950 --> 00:01:46,750 And the direction, right? 31 00:01:46,829 --> 00:01:50,510 The light travels in a straight line 32 00:01:50,510 --> 00:01:52,730 until it hits something. 33 00:01:53,269 --> 00:01:54,750 When it hits something, 34 00:01:54,750 --> 00:02:02,750 Some materials can absorb that light and others can reflect it in a new direction, right? 35 00:02:02,750 --> 00:02:07,750 Reflect the light and change the direction of it. 36 00:02:07,750 --> 00:02:13,750 How the light happens, the artificial one? 37 00:02:13,750 --> 00:02:20,750 When you light a candle, there is a chemical reaction because the candle burns and reacts with the oxygen that we have in the air. 38 00:02:20,750 --> 00:02:26,310 If we don't have oxygen, we cannot have a candle lighting, right? 39 00:02:26,770 --> 00:02:31,689 Similarly, when you turn the torch, right? 40 00:02:31,750 --> 00:02:35,110 When you turn on a torch that is powered with a battery, 41 00:02:35,669 --> 00:02:38,509 a chemical reaction takes place inside the battery. 42 00:02:38,509 --> 00:02:44,789 So that chemical reaction is the one that generates the energy, right? 43 00:02:44,909 --> 00:02:47,789 That's the reason why the torch lights up. 44 00:02:48,669 --> 00:02:50,969 So let's go to move to the next page. 45 00:02:52,090 --> 00:02:59,669 So in this page, we are going to learn about the different types of material and their relationship with the light. 46 00:02:59,669 --> 00:03:05,949 So we have transparent materials, translucent materials and opaque materials, right? 47 00:03:06,590 --> 00:03:12,650 Transparent materials are the ones that let light pass through them, right? 48 00:03:12,710 --> 00:03:15,789 For instance, the glass of your window, right? 49 00:03:15,789 --> 00:03:21,870 You can see clearly what is behind the glass, the window, right? 50 00:03:22,650 --> 00:03:31,469 We also have translucent materials that they let some light pass through them, 51 00:03:31,870 --> 00:03:36,990 but we can see what is behind, but it's not clear, right? 52 00:03:37,710 --> 00:03:42,409 And it's this one. In Spanish, I think it's translúcido, right? 53 00:03:42,409 --> 00:03:50,409 And opaque materials are the ones that do not let light pass through them, right? 54 00:03:50,409 --> 00:04:01,409 A curtain, if you put a curtain at home, or the, I don't know, just a wooden thing outside, right? 55 00:04:01,409 --> 00:04:07,409 So you cannot see what is on the other part of the object, right? 56 00:04:07,409 --> 00:04:11,409 It's really easy, something that you know. 57 00:04:11,409 --> 00:04:25,930 What about the colors? As I told you previously, the sunlight looks like it's white, but it has seven colors, and we have an experiment to see the different colors of light, right? 58 00:04:27,850 --> 00:04:32,750 So light is made up of seven colors, right? The ones that we can find in the rainbow. 59 00:04:33,730 --> 00:04:40,709 So when light hits an object, some colors are absorbed and some are reflected, right? 60 00:04:40,709 --> 00:04:46,110 we only see the colors that are reflected, right? For example, 61 00:04:46,110 --> 00:04:51,870 a tomato only reflects red light and absorbs all the other colors, right? 62 00:04:51,870 --> 00:04:58,709 That's interesting. It's going to, well, I will tell you the activities you have to 63 00:04:58,709 --> 00:05:04,329 do later on. So we are going to move to this new page. I'm gonna make it bigger 64 00:05:04,329 --> 00:05:13,930 for you. So here we have the concepts of reflection and refraction. Reflection occurs 65 00:05:13,930 --> 00:05:20,490 when light hits an object and bounces in another direction and refraction occurs 66 00:05:20,490 --> 00:05:25,129 when light changes the direction and it passes from one material into another, right? 67 00:05:26,329 --> 00:05:34,250 So now we have the concept of reflection. When light hits a smooth surface 68 00:05:34,329 --> 00:05:42,250 all the rays reflect in one direction. As a result, smooth surfaces reflect clear images, 69 00:05:42,250 --> 00:05:51,930 right? But when light hits a rough surface, the rays reflect in many directions. As a result, 70 00:05:51,930 --> 00:05:58,810 rough surfaces do not reflect very clear images, right? And what about the refraction? 71 00:05:58,810 --> 00:06:04,889 Refraction happens when light changes the direction as it passes through a material. 72 00:06:05,850 --> 00:06:14,170 Think of a straw in a glass of water. The straw appears to bend where it enters 73 00:06:14,730 --> 00:06:20,250 the water. This is because the air and water are materials that have different densities. 74 00:06:20,250 --> 00:06:27,050 this is the one that you experienced with the experiment 75 00:06:27,050 --> 00:06:29,790 because at the end of the video I record for you 76 00:06:29,790 --> 00:06:38,670 you have the situation in which I introduced a pen into the water 77 00:06:38,670 --> 00:06:44,250 so you were able to observe what happened 78 00:06:44,250 --> 00:06:47,149 the ones that you have here in this picture, right? 79 00:06:47,149 --> 00:06:52,149 And why mirror and lenses are important here? 80 00:06:52,149 --> 00:06:55,149 Because mirror are the best reflectors, right? 81 00:06:55,149 --> 00:07:05,149 They reflect all the light that hits them, sorry, and they form very clear images of anything that is in front of them. 82 00:07:05,149 --> 00:07:08,149 So that is how a mirror works. 83 00:07:08,149 --> 00:07:14,149 But lenses are pieces of curved glass of plastic that reflect light, right? 84 00:07:14,149 --> 00:07:19,610 We can find them in many objects, such as glasses, cameras, and binoculars, right? 85 00:07:20,269 --> 00:07:24,170 Lenses can make objects look bigger or smaller, right? 86 00:07:25,029 --> 00:07:32,930 So, let's go into move, because we will continue with the next point of the unit, which is new for you. 87 00:07:36,149 --> 00:07:39,949 So, this is the new part of the unit, is the concept of heat. 88 00:07:40,350 --> 00:07:45,810 It's not new for you because in the previous unit, the one related to the sources of energy, 89 00:07:45,810 --> 00:07:52,170 we were talking about it and we talked about this, about the thermal energy. 90 00:07:52,629 --> 00:07:57,230 So it's not new for you, but we are going to learn some other aspects related to it. 91 00:07:57,629 --> 00:08:01,110 So when we heat an object, we add thermal energy. 92 00:08:01,769 --> 00:08:06,750 Thermal energy moves from warmer objects to cooler objects, right? 93 00:08:06,829 --> 00:08:09,889 Remember how the heating works, right? 94 00:08:10,930 --> 00:08:14,949 This flow of thermal energy is called heat. 95 00:08:14,949 --> 00:08:22,250 So, if you are asked about heat, you can get the definition of heat that is on this page. 96 00:08:22,350 --> 00:08:26,490 I'm just going to underline it for you because it's new. 97 00:08:27,329 --> 00:08:31,970 Flow of thermal energy and heat, right? 98 00:08:32,850 --> 00:08:39,809 And important, thermal energy moves from warmer objects to cooler objects. 99 00:08:39,950 --> 00:08:50,850 right yes i want to save the changes right conductors and insulators one of the properties 100 00:08:50,850 --> 00:08:58,129 of material is how well they conduct heat thermal conductors transfer heat very well 101 00:08:58,769 --> 00:09:05,090 metals such as copper and aluminium are excellent excellent conductors so we use them to make 102 00:09:05,090 --> 00:09:17,009 cooking pots and pans. They conduct heat from the cooker to the food very quickly. 103 00:09:19,889 --> 00:09:26,769 Thermal insulators do not transfer heat very well. Some examples are wood, plastic and wool. 104 00:09:27,409 --> 00:09:33,970 When we wear woolen gloves on a cold day, only a little heat escapes through the wool, 105 00:09:33,970 --> 00:09:40,690 so our hands stay warm. So we also have the cooking gloves, the ones that when we 106 00:09:40,690 --> 00:09:46,690 are taking something from the oven we use special gloves, so it's because they 107 00:09:46,690 --> 00:09:52,629 are thermal insulators too, right? They are made of a material which is thermal 108 00:09:52,629 --> 00:09:59,649 insulator. That's the correct sentence, right? So it's something really easy for you to 109 00:09:59,649 --> 00:10:05,649 know? What are thermal conductors and what are thermal insulators, right? 110 00:10:05,649 --> 00:10:12,250 Effects of thermal energy. When we add thermal energy to a substance, there can 111 00:10:12,250 --> 00:10:18,269 be a change of state or volume, right? Think about the ice, for instance. 112 00:10:18,269 --> 00:10:24,149 Melting. The thermal energy of a solid increases and it changes to a liquid. 113 00:10:24,149 --> 00:10:29,049 Here we have the example of the butter. You can see, yes, it was cold 114 00:10:29,649 --> 00:10:39,649 and it was forming like a solid cube, right? But now it's just like an oil, it's a liquid. 115 00:10:40,289 --> 00:10:47,490 Evaporation, the thermal energy of a liquid increases and it changes into a gas, right? 116 00:10:47,490 --> 00:10:53,009 Something really easy for you because you have learned about it in previous years in the previous 117 00:10:53,009 --> 00:10:58,649 unit and expansion. When the thermal energy of a substance increase, its 118 00:10:58,649 --> 00:11:06,029 volume increases. So, this is the end of the unit because the next point is that 119 00:11:06,029 --> 00:11:13,190 related to something to learn more. I would like you to have a look on it, 120 00:11:13,190 --> 00:11:21,889 right? But you have learned about it in the social science units related to the 121 00:11:21,889 --> 00:11:31,190 population because you have an activity that I think was in the Genially related 122 00:11:31,190 --> 00:11:45,389 to light and night light and and the population right so you here says get 123 00:11:45,389 --> 00:11:56,190 to pearls, you can't do it, so just read the text A and B. The B is on page 95, right? And you can 124 00:11:56,190 --> 00:12:02,029 learn about it, right? About artificial light, the light that we can see during the night, right? In 125 00:12:02,029 --> 00:12:10,909 the cities, right? But what I would like you to do, sorry, is to do the following activities. 126 00:12:10,909 --> 00:12:24,279 Let's move to the review. And you are going to do the following activities. Take notes. 127 00:12:24,279 --> 00:12:34,629 Copy your graphic organizer in your notebook and classify the words from the box below. I want you 128 00:12:34,629 --> 00:12:39,710 to do this one because it helps you to create mind maps in the future or to learn how to do 129 00:12:39,710 --> 00:12:44,570 them because we are starting creating mind maps the class right so please do 130 00:12:44,570 --> 00:12:52,429 the first one copy the boxes please please clean clean use the ruler you 131 00:12:52,429 --> 00:12:56,929 need it use different colors use the complete page don't do it just in a 132 00:12:56,929 --> 00:13:07,899 small corner of it right the activity the two and three you don't have to do 133 00:13:07,899 --> 00:13:17,860 because I prefer you to focus on these ones on the far right so you have to 134 00:13:17,860 --> 00:13:24,940 decide whether these words are a source a natural light sources or artificial 135 00:13:24,940 --> 00:13:32,700 light sources because you will have a similar activity on the exam five right 136 00:13:32,700 --> 00:13:40,379 you just have to copy the ones that are true, but I don't want people writing false, false, 137 00:13:40,379 --> 00:13:46,679 false, false, false, false, false, false, false, no, right? So, do it correctly because if not, 138 00:13:46,679 --> 00:13:52,379 you will repeat it, as simple as that, right? Because when you have to copy just the true ones, 139 00:13:52,379 --> 00:13:56,879 you write in all of them false, false, false, false, false, and I did a homework, no, 140 00:13:56,879 --> 00:14:00,899 it doesn't work for me, no, no me vale, no funciona 141 00:14:00,899 --> 00:14:04,940 right, this is six 142 00:14:04,940 --> 00:14:09,059 describe what is happening in the photos, this is very easy because you just have to write 143 00:14:09,059 --> 00:14:11,700 A, a word, B, and a word, right 144 00:14:11,700 --> 00:14:16,320 and so we have to do one 145 00:14:16,320 --> 00:14:20,379 four, five, six 146 00:14:20,379 --> 00:14:26,539 and nine, that's all, right 147 00:14:26,539 --> 00:14:31,460 those are the activities that you have to do, I don't have more time 148 00:14:31,460 --> 00:14:35,720 if you have any doubt just let me know and that's all 149 00:14:35,720 --> 00:14:39,919 I don't have more time, right? Please study for the exam 150 00:14:39,919 --> 00:14:43,220 the exam will be during the connection so you won't copy it 151 00:14:43,220 --> 00:14:47,759 on it, so please study because it's something positive 152 00:14:47,759 --> 00:14:51,620 for you, right? And I'll see you on Wednesday 153 00:14:51,620 --> 00:14:54,019 Bye! See you!