I think it’s the one that has a Br
Answer:
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (the electromagnetic, weak, and strong interactions, and not including the gravitational force) in the universe, as well as classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, through the work of many scientists around the world, with the current formulation being finalized in the mid-1970s upon experimental confirmation of the existence of quarks.
heterogeneous mixture, because, the layers are called phases and a heterogeneous mixture has two or more phases. the oil phase is less dense then water so it floats on top, etc.
When you add salt to water, you lower to freezing point of the substance.
So for example, normal water freezes at 0°C. But water with salt in it won't freeze at 0°C, because its freezing point is lowered.
In answer to the question. It takes longer for water with salt in it to freeze because the substance requires a lower temperature than normal water to freeze.