Nader+Mekheal

I found something interesting about the artificial turf that retains heat and become very worm on the sunny days. They found that when the air temperature of the day increased by 2.1 Celsius, the turf temperature increased by 3.5 Celsius. They said that on hot days the colored polymers absorb the sun’s energy efficiently, and the field can get warm. The manufacturer recommends spraying the field with water before the game. That’s because the water has a high heat capacity that makes the system more resistant to temperature change. (89 words)

=**How does solar power work?**= I read the article on how does the solar power work. One of the things that interest me in this article is how they convert sunlight to electricity. They uses large crystals made out of silicon, which produces electrical current when struck by light. In a crystal, the bonds between silicon atoms are made of electrons that are shared between all of the atoms of the crystal. When the light gets absorbed, one of these electrons gets excited up to a higher energy level. That electron can then move around crystal freely. Then we can get a current. They said that there are newer materials that can turn light into electricity. These materials use smaller and cheaper crystals, but they are not good as silicon at turning light into electricity. Some of these materials are copper, indium, and gallium. (140 words)

**Einstein's Miracle Year**

One thing that I have learned is that photoelectric effect occurs when you shine light on a metal surface and electrons fly off. Also, Newton’s law predict that the more intense the light, the better chance that electrons are ejected from the metal surface. So that means that the more light that we have, the better chance of seeing that object. I liked the idea of the clock and the spaceship that travels at the same speed of light. So as you travel the clock will appear to have stopped. That happened because the light that comes from the clock can’t reach you since you and light travel at the same speed and you left first. Now, Einstein successfully showed that as you approach the speed of light, time and space are compressed. (135 words) The Many Looks of the Periodic Table: **

Periodic table is just an amazing way to organize our 117 elements. Periodic table is very helpful for every body. It helps to organize people’s thoughts about elements and their properties. It lists the elements in order of increasing atomic number. That helps you to know a lot of information like the number of particles that found in those element. Scientists spend too many years trying to organize the periodic table. I found that Charles Janet’s periodic table is very similar to the periodic table that we have now. His periodic table contains four blocks that contain a decreasing number of rows. He arranged the periodic table from right to left (opposite to the periodic table that we have now). I also liked the idea of the chemical galaxy, but it’s a little bit hard to understand. Periodic table is really a very helpful tool, I’m very glad that we a such that thing now.