https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0 en-us 2017-01-03 19:18:02 UTC 2024-07-15 19:02:57 UTC hello@padlet.com saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145159008 Symbol He
Atomic number 2
Atomic weight 4 g/mol.]]> 2017-01-03 19:30:38 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145159008 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145159857 Helium is composed of two electrons in atomic orbitals and the nucleus contains two protons and two neutrons. (1s²).]]> 2017-01-03 19:34:05 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145159857 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145160712 Melting point -272,2 ºC
Boiling point -268,6 ºC
The normal phase is gas.
It's a noble gas.]]> 2017-01-03 19:37:47 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145160712 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145161356 This element was discovered in 1868 by Pierre Janssen and Norman Lockyer]]> 2017-01-03 19:40:45 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145161356 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145162296 2017-01-03 19:45:03 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145162296 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145162832 Helium can be used to find leaks because is very small gas and can finds the smallest holes and it's very light too.
Helium is the most unreactive element.
It exists as isolated atoms.
Helium can't be synthesized in nature because it is just an element.

]]> 2017-01-03 19:47:16 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145162832 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145164051 In the past Hydrogen be used to fill balloons and actually we can use Helium to do it. 
If you fill a balloon with Hydrogen and add a match, it will burn quickly and energetically because it makes water but if you do it with a balloon filled with Helium it will explode but it didn't burn. It's unreactive, it's an inert gas.
If you freeze a balloon of Helium, the gasses inside slow's down because it take up much less volume. 
If you breathe Helium you start speaking like Donald Duck because the speed of sound is much greater in Helium that it is in ordinary gases.]]> 2017-01-03 19:52:58 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145164051 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145167521 If you cold things with liquid Helium you get very strange properties. You can make some materials lose their electrical resistence. It is used for magnets when you need very powerful magnets and we use this magnets from magnetic resonance imaging in hospitals.
Helium is very important for all sorts of refrigeration.]]> 2017-01-03 20:11:22 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145167521 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145170194 2017-01-03 20:25:52 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145170194 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145170373 1. What can you do if you want to speak like Donald Duck? Why does it happen?
2. What happen if you add a match in a balloon filled with Hydrogen?
3. What do you learn about the things freezed with Helium?
4. Now you know the ballons filled with Helium are so lights. What  happen if you turn loose it?
5. According to the video, why nowadays we use Helium to fill balloons and not Hydrogen? How much does Hydrogen and Helium molecule weight? ]]> 2017-01-03 20:27:20 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145170373 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145172697 2017-01-03 20:45:34 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145172697 saragonzalezmorillas https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145173158 2017-01-03 20:49:24 UTC https://padlet.com/saragonzalezmorillas/c67mkuqlf4n0/wish/145173158