Mrs Cameron 2014: SALT Vs ICE

This week one of our groups read an explanation on 'Why the sea is salty'.
From there we decided to look a little further into salt and water.

Mrs Cameron tried to colour some water to match our table groups. She had the great idea of freezing the water in the shape of hands using rubber gloves. Unfortunately, Mrs Cameron snapped off lots of fingers when removing the rubber gloves!

Learning Intentions: WALT…

· Acknowledge the 3 states of water – Solid, liquid, gas

· Pure water has a freezing point of 0°C and by adding salt or another substance to the water we are lowering the freezing point.

· Recognise some chemical terms such as H2O for water, NaCl for Sodium Chloride.

· Give an explanation as to why Sodium Chloride is a useful substance in icy conditions.

Big Ideas about Water

· Water can exist in three states: solid, liquid, or gas

· During a change of state, water undergoes one of the following processes: freezing, melting, dissolving, boiling, evaporating, or condensing. These are all physical changes.

· All these processes are reversible.

· When water freezes, it changes into ice.

· When ice melts, it changes into water.

· When liquid water boils, it evaporates and changes into steam.

· When steam condenses, it changes into liquid water.

· Adding certain substances to water changes the temperature at which some changes of state occur.