Scientific Method & BTB

Look at the diagram. The liquid in the test tubes is bromothymol blue (BTB). The object in the test tube is Elodea, a plant that grows in water. Why are some of the tubes a yellow/green colour?

• The artist likes green.

• The BTB does not contain CO2.

• The BTB contains CO2.

• BTB is normally green.

Tags

NGSS.MS-LS1-6

Look at the diagram. The liquid in the test tubes is bromothymol blue (BTB). The object in the test tube is Elodea, a plant that grows in water. In this science experiment, what would you call Tube 3?

• The independent variable tube.

• The dependent variable tube.

• The control experiment/tube.

• The extra tube.

• The hypothesis tube.

Tags

NGSS.MS-ETS1-1

Look at the diagram. The liquid in the test tubes is bromothymol blue (BTB). The object in the test tube is Elodea, a plant that grows in water. Explain why Tube 3 is necessary.

• To see if BTB changes on its own without elodea.

• In case the scientist comes up with another idea.

• To see the effect of temperature on BTB.

• Science experiments are always done in sets of 3.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

Look at the diagram. The liquid in the test tubes is bromothymol blue (BTB). The object in the test tube is Elodea, a plant that grows in water. Why did Tube 2 change colour?

• Light caused the BTB to change colour.

• CO2 escaped from the tube into the air.

• The plant gave CO2 to the BTB.

• The plant absorbed (took in) the CO2 during the process of photosynthesis.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

Look at the diagram. The liquid in the test tubes is bromothymol blue (BTB). The object in the test tube is Elodea, a plant that grows in water. Suggest a reason why Tube 1 did not change colour.

• The plant was dead.

• The green film helped with photosynthesis.

• The green film somehow stopped photosynthesis.

• There was no CO2 in the tube with the green film.

• The green film made the tube warmer which kept it green.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3