Gas is not prepared from sand.
Sand and water do not react, they simply mix. This is a physical process.
No. It's a physical reaction.
No, it is a physical reaction because it doesn't undergo any change in chemical properties.
No, separating sand from water by filtration is a physical process, not a chemical reaction. This process involves passing the mixture through a filter to physically separate the solid particles from the liquid.
Adding sand and water is a physical change because no new substances are formed. The sand particles remain as they are and simply mix with the water, without any chemical bonds being broken or formed.
The Journey into the hole
physical
Physical because you are not changing the substance.
Chemical
Making glass from sand is a physical because the actual composition of the substance (silica) is not changing. Making glass is just melting all the bits of sand into a large piece (glass).
Chemical
Physical