2. The Image to the far right. It's rice I believe.
Explanation:
A lustrous material is a material that shine or usually reflect light. Fire isn't a material and the powder is dull and doesn't shine. In this case the diamond is a lustrous material and not a metal.
An edible substance is anything thing that can be consumed as food. Soap is consumable and the blue picture is definetly not either so we conclude that the rice is the edible option.
You would not want to use a stopper when<span> combining two unknown substances because the gasses made from the combination could end up creating to much pressure and explode.</span>
