Color swirls

Color Swirls

NGSS

Students use a model to investigate how temperature-driven density changes can cause convection in a fluidStudents use evidence to construct an explanation of how temperature-driven density changes can cause convection in a fluid

Which square has more dots?Which square is bigger?

square 2

square 1

square 2

square 1

Both squares have the same number of dots in a given amount of space

Which square has more dots?Which square is bigger?

square 2

square 1

square 2

square 1

Both squares have the same number of dots in a given amount of space

Which ball has a higher density?

golf ballping pong ball

Convection

COOLING

HEATING

Wikimedia Commons

Convection cell

Convection cell

Convection drives plate tectonics

Convection creates wind

CER TableCLAIM

What do you know?EVIDENCE

How do you know that?

REASONINGWhy does your evidence

support your claim?

Warm water rises.The red food coloring moved up after being warmed by the candle.

The red food coloring sat on the bottom of the bowl until it was heated by the candle.

Warm water is less dense.    

 The blue food coloring on the sides of the bowl sank to the bottom.

There is an instability in this system.

 The water in the bowl eventually turned purple.