Understanding the Kilogram and its Redefinition

The video explores the history and evolution of the kilogram, highlighting its initial definition based on water and its current reliance on the International Prototype Kilogram. It discusses the challenges of using a physical object as a standard and introduces efforts to redefine the kilogram using silicon spheres and Avogadro's constant. The video also touches on alternative methods like the Watt Balance and the potential for a new definition that is independent of physical objects.

What makes the silicon sphere unique compared to other objects?

• It is the heaviest object in the world.

• It is the roundest object ever created.

• It is the largest object made of silicon.

• It is the most colorful object in the world.

Why was the original unit of mass called 'grave' replaced?

• It was too large for practical use.

• It was too similar to a noble title.

• It was too difficult to pronounce.

• It was too small for practical use.

What is the International Prototype Kilogram also known as?

• Le Grand K

• Le Petit Gram

• Le Petit K

• Le Moyen K

What problem was discovered with the International Prototype Kilogram and its replicas?

• They were made of different materials.

• Their masses diverged over time.

• They were all identical in mass.

• They were stored in different locations.

How does the silicon sphere help in redefining the kilogram?

• By being the heaviest object.

• By allowing the calculation of the number of atoms.

• By being the most colorful object.

• By being the largest object.

What is the significance of using silicon-28 in the sphere?

• It is the most expensive isotope of silicon.

• It is the purest form of silicon.

• It is the only isotope of silicon.

• It is the most common isotope of silicon.

What is Avogadro's constant currently based on?

• The number of atoms in a liter of water.

• The number of atoms in twelve grams of carbon-12.

• The number of atoms in a kilogram of silicon-28.

• The number of atoms in a gram of carbon-12.

What is one alternative approach to redefining the kilogram?

• Using a silicon sphere to fix Planck's constant.

• Using a liter of water to fix Planck's constant.

• Using a platinum-iridium cylinder to fix Planck's constant.

• Using a Watt Balance to fix Planck's constant.

What was the original intention for the mass of a kilogram?

• The mass of a liter of water at its densest temperature.

• The mass of a liter of water at its freezing point.

• The mass of a liter of water at its boiling point.

• The mass of a liter of water at room temperature.

Who was involved in the definition of the kilogram from its inception?

• Antoine Lavoisier

• Isaac Newton

• Albert Einstein

• Marie Curie