Photochemical reactions

Question 1

What is a photochemical reaction?

Answer 1

A reaction that gets the energy it needs from light

Question 2

Define photosynthesis

Answer 2

The reaction between carbon dioxide and water in the presence of chlorophyll and sunlight to produce glucose and oxygen.

Question 3

Symbol equation for photosynthesis

Answer 3

6CO2 + 6 H2O →(“UV light” ) C6H12O6 + 6O2

Question 4

What is a silver halide?

Answer 4

A compound made up of silver and a halogen

Question 5

What happens first when light enters the camera and strikes the film?

Answer 5

Light enters and hits the silver bromide on the film. Silver ions are reduced to form silver metal. Silver metal creates dark areas on the photographic film.

Question 6

How is the film developed?

Answer 6

Unreacted silver bromide is washed away, leaving clear areas on the film. Silver remains, giving dark areas. The film is printed by shining light through the film and onto photographic paper coated with silver bromide

Question 7

How is the black and white image produced

Answer 7

Light passes through clear areas of the film more easily. and causes the silver ions to bereduced to silver. Dark areas block off light. The unreacted silver halide is washed away from the paper