Any letters that follow will be lower case letters, for example, helium is ... as a non-metal. Hydrogen is placed on its own as it is quite a unique element. The periodic table can be read across ...

Despite billions of years of countless stars fusing hydrogen into helium it still makes up 75 per cent of the detectable content ... Now next week we meet the time keeper of the periodic table. One ...

Hello, this week we're almost at the top of the periodic table because we're taking a look at the lighter than air gas helium ... The sun is comprised of about 75% by mass of hydrogen and 24% of ...

Here are some popular mnemonics to help you remember the first 20 elements of the periodic table: H - Hydrogen He - Helium Li - Lithium Be - Beryllium ...

Each energy level holds a certain number of electrons before electrons go into the next level. 1st Period: Hydrogen and helium—Electrons go into the first energy level. After the first level has two ...