Introduction

As you will see in the first link of YouTube all in the world is considered material, and every material works in three different states of the material, the states are: solid, liquid and gas, solid is every material that you can touch grab with your hand like the computer or cellphone or tablet in which you are seeing this, solid is every material that you can touch and grab, the state of liquid is easy to explain, liquids are everything that share characteristics with water and the easiest example of the liquids is the water, there are another examples of liquids like juice, soda, etc. Liquids as solids are material that you can touch with your hand but there is a difference between liquids and solids, solids are the material that you can touch but also you can grab with your hand and liquids are the material that you can touch with your hand, but you cannot grab water. Gas is the material that you cannot even see, the gases are material that you cannot touch or see, the easiest example of a gas is the air, the air is the most common gas. When you boil the water, it changes of state of the material from liquid to gas, so you cannot see gas water, but it is there.
And as you can see in the second video a catalyzer is basically a substance that speed up a reaction, the chemical definition of a catalyzer is some chemical that accelerates a process.
A chemical process is the process that make some change in the material, when a solid change to liquid is a chemical process, when the water is boiling till evaporating it is a chemical process. So, how does this concept fit in this experiment? Well, the experiment is making ice cream without a fridge and we will do it by using a common catalyzer. Our experiment consists in having the ice in a big bowl and having the juice on a bowl smaller than the bowl with ice, but how does the concept of catalyzer is applicated to this? In the ice bowl we put a lot of grain salt, this is the catalyzer, and the salt accelerates the process of melting in the ice but between this process and the moment when there is only cold water, there is a process of reduction of the congelation point of the ice which means that the ice gets colder than its normal temperature at melting time, this extra cold is what makes the experiment successful.