Inside the Atom

In the picture

1. 1The dense central core: where almost all of the atom’s mass is packed
2. 2A particle orbiting close to the core
3. 3The path a particle follows around the core
4. 4A particle orbiting farther from the core, in an outer path

Examples

• If an atom were the size of a football stadium, its core would be about the size of a marble at the center.
• The way a few dust specks might drift around a bright lamp in an otherwise dark room, far from the bulb.

Quiz: Inside the Atom (Age 15)

1. 1

   Which part of an atom contains almost all of its mass?

   • The paths the particles follow around the core
   • The tiny core at its center
   • The particles moving around the core
2. 2

   Why is it surprising that the core holds almost all of the atom’s mass?

   • Because the core takes up only a tiny fraction of the atom’s space
   • Because the core is the same size as the whole atom
   • Because the core moves faster than the other particles
3. 3

   How do the particles around the core move?

   • They travel at different distances from the core, each in its own path
   • They all travel along the exact same path at the same distance
   • They move with no defined path at all

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.