Melting is a process involving absorption of energy which means that it is endothermic.
Answer=4
Only solids can create regular geometric patterns... CO2 is a gas, H2O is a liquid and Sodium Chloride doesn't count because it's dissolved in a solution...
The answer is b. Mass of the atoms
This is because of the law of conservation of mass. This means the mass in a system (in this case the reaction) can't change, so the quantity can't be added or removed
