Quiz: How Much Do You Know About Hydrogen and Fuel Cells?

Hydrogen and fuel cell technologies power cars, buildings and more. But how much do you know about them? Test your knowledge with this quiz!

1. How do fuel cells generate electricity?



Electrochemical reaction

Organic reaction

Much like a battery, a fuel cell produces electricity through an electrochemical reaction, which generates electricity without any combustion. Unlike batteries, fuel cells don't wear out and continuously provide electricity as long as there's a constant source of fuel and oxygen.

2. What do fuel cells emit?





Fuel cells typically generate electricity using hydrogen and emit only water and heat. For polymer electrolyte membrane (PEM) fuel cells, hydrogen is fed into one side of the fuel cell, and oxygen is fed into the other. Hydrogen ions pass through a membrane and react with the oxygen on the other side to form H2O (or water) and create electricity.

3. When was the first fuel cell invented?





Welsh scientist Sir William Robert Grove is credited for inventing fuel cells in 1839. However, the technology wasn't used commercially until the 1960s.

4. How do you boost the amount of electricity a fuel cell system produces?

Adding oxygen

Adding hydrogen

Adding cells

Adding protons

A single fuel cell produces about one volt of power. To increase the amount of electricity generated, individual fuel cells are combined to create a fuel cell stack. Depending on the application, a fuel cell stack might only contain a few cells, such as when used for portable power generation for laptops or other consumer electronics, or hundreds of individual cells, like when used to power passenger vehicles.

5. When were fuel cells first used in space?

Apollo Program

Space Shuttle Program

Project Mercury

Gemini Program

NASA first used fuel cells in 1965 to power onboard electronics during the Gemini 5 mission, which broke the world's manned spaceflight endurance record. Fuel cells not only provided power but also water for astronauts. The technology improved and was used on all subsequent manned space missions including the Apollo and Space Shuttle programs.

6. Globally, how many hydrogen fuel cell cars are on the road?





Many countries in Europe, the Americas, and Asia have deployed hydrogen fuel cell cars as part of their national hydrogen strategy. These countries are part of the International Partnership for Hydrogen and Fuel Cells in the Economy―a government to government partnership with more than 20 country members and the European commission working together to accelerate progress in hydrogen and fuel cells. There are currently two fuel cell passenger vehicles in production—the Toyota Mirai and Hyundai Nexo—and multiple companies are developing commercial trucks powered by hydrogen.

7. What are the two most common ways to produce hydrogen gas used in fuel cells?

Electromagnetism and quantum mechanics

Steam reforming and electrolysis

Electrolysis and absorption

Thermal conductivity and refraction

Since hydrogen does not exist as a gas on Earth, it must be separated from other elements. Hydrogen atoms can be separated from water, natural gas molecules or biomass. The two most common ways to produce hydrogen are steam reforming (using high-temperature steam to produce hydrogen from natural gas) and electrolysis (splitting water).

8. How do you refuel a fuel cell electric vehicle?

Fill the tank with water

Plug the vehicle into a charging station

Pump hydrogen gas directly into the tank

Pump gasoline into the tank

To refill a fuel cell electric vehicle, you pump hydrogen gas from a hydrogen fueling station directly into the tank. Fuel cell electric vehicles can have a driving range of more than 300 miles on one tank of hydrogen. Since fuel cell systems are more than two times as efficient as an internal combustion engine, you need half the amount of hydrogen to go just as far.

9. In general, how much hydrogen is produced in the United States every year?

10 million metric tons

200,000 metric tons

100 million metric tons

2 million metric tons

Hydrogen is a standard industrial chemical commodity today. In the United States, approximately 10 million metric tons of hydrogen are produced every year, most of which is used for petroleum recovery and refining purposes as well as fertilizer (ammonia) production.

10. Which state has the most hydrogen fueling stations?





There are more than 45 public hydrogen fueling stations up and running in California, with plans in place for more than 175 stations by 2026. Use EERE's Alternative Fueling Station Locator to find stations in the United States and Canada.

11. How much of the known universe mass is made up of hydrogen?

99 percent

75 percent

25 percent

50 percent

Hydrogen is the most abundant element in the universe. About 75 percent of all matter is composed of hydrogen.

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