Macro-Scale Observations
Molecular scale observations
Energy Transfers
Attraction
The Big Mystery
100

Change where a liquid turns into a gas, like the Titan lake disappearing.

Evaporation

100

A solid's molecules are best described as moving only in this way.

Moving in place or vibrating

100

What measurement (in the sim) tells us the average speed of particles?

Temperature

100

The term for the forces that exist between molecules, which holds the substance together.

Molecular attraction

100

This moon of Saturn has a disappearing methane lake.

Titan

200

What phase change is freezing the opposite of?

Melting

200

What happens to particle speed when temperature increases?

They move faster

200

Energy must be transferred into a substance for this phase change to occur, going from liquid to gas.

Evaporation

200

The name of 2 forces that that are always in a game of "Tug of War" to win the phase changes

Kinetic Energy and Molecular attraction

200

The main substance that formed the lake on Titan.

Methane

300

The phase change where energy is removed from a liquid, causing it to become a solid.

Freezing

300

The molecules in a liquid have enough freedom of movement to do this, allowing the substance to flow.

Move around each other

300

When a liquid turns into a solid, this kind of energy is transferred

Transferred out

300

Transferring energy into a substance increases the _____ energy of its molecules.

Kinetic Energy

300

The phase change that would result if energy were transferred out of the liquid methane lake.

Freezing

400

What must be added or removed for a phase change to happen?

Energy

400

A gas's molecules have enough kinetic energy to this

Move away from each other

400

A phase change happens when kinetic energy overcomes molecular _____.


attraction 

400

This kind of attraction overcomes Kinetic Energy being Transferred out 

Strong Attraction

400

What likely happened to Titan's lake between 2007 and 2009?

It Evaporated

500

This change is where a gas turns into a liquid, often seen as dew on a cold morning

Condensation

500

During a phase change, this molecular movement  changes, causing a macro-scale change in appearance.

freedom of movement

500

Scientists digging in a cave found an unknown substance. The scientists found that the substance’s molecules were moving around each other. The scientists increased the speed of the substance’s molecules and caused a phase change.How did the scientists do this, and how did this affect the substance?

The scientists transferred energy . . .

a into the substance, and the substance changed into a gas.

500

Substances with stronger molecular attraction need more energy for this to happen (melting or boiling).

Phase Change

500

Why didn't the methane lake evaporate before 2007?

enough energy was NOT transferred Into THE LAKE to overcome molecular attraction?