# 2nd Grade Science : Argue changes caused by heating/cooling can't be reversed

## Example Questions

### Example Question #1 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Today Patrick and Annie's mother made French toast for breakfast. She asks them if the changes to the bread can be reversed or not. Annie says the changes cannot be reversed, and Patrick says the changes can be reversed. Using this example, who is correct, Annie or Patrick, and why?

Patrick; He is correct because the changes to the bread can be reversed. The bread would be able to be cooked and then turned back into plain bread.

Annie; She is correct because this is a change that cannot be reversed. If the bread has been cooked and made into French toast, it cannot be turned back into plain bread.

There is not enough information to decide who is correct.

Neither; Annie and Patrick are both incorrect.

Annie; She is correct because this is a change that cannot be reversed. If the bread has been cooked and made into French toast, it cannot be turned back into plain bread.

Explanation:

In the situation presented, Annie is correct. The changes to the bread are not able to be reversed once it has been heated up and turned into French toast. In some instances, these changes can be reversed like an ice cube or chocolate bar. If these items are melted, they can be cooled and will return to a solid. Once the bread is cooked, it cannot be changed back.

### Example Question #81 : Physical Science

Today is the 4th of July, and Sammie's dad celebrated with fireworks. He lit them in the yard for everyone to see. His dad asks them if the changes made to the fireworks can be reversed or not. Sammie says the changes cannot be reversed, and his dad says the changes can be reversed. Using this example, which is correct, Sammie, or his father, and why?

Sammie's father; He is incorrect in this situation because the changes to the fireworks from being heated cannot be reversed. He thinks they can be reversed.

Neither; both Sammie and his father are wrong

Sammie; He is correct in this situation because the changes to the fireworks from being heated cannot be reversed.

There is not enough information to decide who is correct.

Sammie; He is correct in this situation because the changes to the fireworks from being heated cannot be reversed.

Explanation:

Sammie is correct in this situation. Once the fireworks are lit and the explosion happens, there is no way for this change to be reversed. The firework cannot be "unlit" and put back into the container once the heat has been applied. Something like a chocolate bar can have heat applied and then reversed once it is cooled, but fireworks are an example of something that cannot be changed.

### Example Question #1 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Some changes caused by heating and cooling cannot be reversed.

False

True

True

Explanation:

The statement in the question is correct. Some changes can be reversed when something is heated or cooled, and others cannot. Boiling water can be reversed, once the steam cools it is liquid water again. Lighting a piece of paper on fire cannot be reversed; the paper cannot be returned to its original state.

### Example Question #4 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Which of these photos demonstrates a change from heating or cooling that cannot be reversed?

Explanation:

The photo that demonstrates a change that cannot be reversed is the pan of brownies. Writing with markers can be erased and reversed, ice cubes can be heated and cooled multiple times between states, and a puzzle can be taken apart and put back together. Once the ingredients are mixed into a batter and then heated, the brownies cannot be turned into mixture again.

### Example Question #1 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

The photo below is an example of a change that cannot be reversed.

False

True

False

Explanation:

The photo is an example of a change that CAN be reversed. If the large block of ice starts to melt and the temperature drops again, it will refreeze. If the Sun comes out and it warms up, it will begin to melt again.

### Example Question #1 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Becky says some changes caused by heating cannot be reversed. Maddy says all changes can be reversed. Their mother cooked hashbrowns for breakfast. Using this example, which sister is correct, Becky or Maddy, and why?

Maddy; the potato can be uncooked and put back into its original form

There is not enough information to tell who is correct or incorrect

Becky; once the potato has been cooked there is no way to reverse it back into the form it was before

Neither; neither Becky nor her sister Maddy is correct

Becky; once the potato has been cooked there is no way to reverse it back into the form it was before

Explanation:

Some changes caused by heating or cooling cannot be reversed. This statement is true, so in the cases of Becky and her sister Maddy, Becky is correct. Some changes caused by heating, like cooking a potato, can't be reversed. There is no way to take the potato from cooked and get it back into its raw form.

### Example Question #2 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Which of these photos demonstrates a change from heating or cooling that cannot be reversed?

Explanation:

The photo that demonstrates a change that cannot be reversed is the plate of pancakes. Water that has been frozen into snow can be turned back to a liquid, and ice cream and popsicles can be refrozen if melted. Once the ingredients are mixed into a batter and then heated, the pancakes cannot be turned into mixture again.

### Example Question #11 : Changes Caused By Heating And Cooling

The photo below is an example of a change that cannot be reversed.

True

False

True

Explanation:

The photo is an example of a change that can't be reversed. Once the marshmallows have been roasted and start to cook, they cannot be changed back. There is no way to change melted marshmallows back to their original form.

### Example Question #1 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

The photo below is an example of a heating or cooling change that cannot be reversed.

False

True

True

Explanation:

The photo demonstrates a change that cannot be reversed. Once the toast is cooked and the butter melts into it, the changes cannot be reversed. Even if the toast is put into the refrigerator, it will not return to a piece of plain bread. A chemical change has taken place and cannot be reversed.

### Example Question #3 : Argue Changes Caused By Heating/Cooling Can't Be Reversed

Which answer choice is a change caused by heating or cooling?

Cutting a banana