Water molecules freeze in a hexagonal pattern and the molecules are further apart than they were as liquid water. Water is unusual because its molecules move further apart when it freezes. The ...

Heating a substance makes the molecules move faster. Cooling a substance makes the molecules move slower. Students see a video of water freezing and then melting. Students warm butter until it melts ...

the molecules in the food slow down, making it almost impossible for bacteria to multiply. When food freezes, small ice crystals form inside it. The speed of freezing is key here: the faster the ...