Amani wants to know if crushed ice or whole ice melts faster. She puts the whole ice in a bowl on the kitchen counter. She puts the crushed ice in a bowl in the oven. Lastly, she times both bowls of ice to see which melts fastest. Is this a valid experiment? Why or why not?

Yes,

     Because she wants to know which melts faster so she puts a bowl of crushed ice in a oven, which in then can melt it. If she turns on the oven light she will be able to understand if it melts.

If she leaves it out on the counter the regular un-crushed ice, she can see if that is also melted faster but this is in fact a valid experiment.