Answer:
Hydrogen:
Hydrogen is the most abundant element on earth.
Fuel cells can be used to power several applications.
Fuel cells are a clean way to produce power.
Fuel cell cars are very similar to traditional gasoline powered cars
same thingy:
they are both elements
both of them are air
Helium:
Helium is the second most abundant element in the universe, and the second lightest element.
It is estimated that our sun produces 700 million tons of helium per second.
Helium has the lowest boiling point of all elements—4.2 degrees Kelvin (that -268.8 Celsius)—just 4 degrees above absolute zero.
