Uranium was first discovered when people were mining ___.

• gold

• silver

• copper

• lead

The rock containing uranium was called:

• pitchrock

• pitchblende

• uraniumblende

• radiorock

Henri Becquerel wrapped ___ in dark paper and putting a chunk of rock containing uranium on top of it.

• photographic film

• a digital camera

• a thin piece of silver

• a window

Tags

NGSS.HS-PS1-8

Henri Becquerel then placed everything in sunlight. After unwrapping it, he noticed that the photographic film was "exposed". It was as if sunlight shined directly on it. This was ___ since the photographic film was COVERED with dark paper.

• impossible

• a reasonable explanation

Tags

NGSS.HS-PS4-3

So Becquerel concluded that ____ must be absorbing the sunlight and transferring this energy to the photographic film through the paper!

• the paper

• the rock containing uranium

Tags

NGSS.HS-PS4-3

To test this, Becquerel wrapped a new piece of film in paper and put the uranium containing rock on top once again. He was going to put it on the window ledge but noticed that it was…

• cloudy out, so he left it on the ledge anyway

• cloudy out, so he put it in a dark drawer

• sunny out, so he put it on the ledge in the sunlight

Becquerel took the film wrapped in paper with the rock on top out of the drawer, unwrapped it, and noticed that it had been exposed once again, despite being in a dark drawer! He realized the energy required to expose the film:

• definitely came from sunlight and had nothing to do with the rock

• came from the rock itself and had nothing to do with sunlight

Tags

NGSS.HS-PS1-8

Becquerel's FINAL conclusion was that:

• the rock released its own energy that exposed the film, even when it was in the dark

• the rock absorbed the sun's energy and then transferred it to the photographic film days later

• the rock had nothing to do with the change on the photographic film

Years later, scientists finally understood what caused the rock containing uranium to expose the film. They realized that it contained unstable atoms of ____.

• Uranium-238

• Thorium-234

• Helium-4

• Lead-207

Tags

NGSS.HS-PS1-8

The nucleus of these U-238 atoms were ____ and underwent radioactive decay.

• stable

• unstable

Tags

NGSS.HS-PS1-8