A scientist mixes two liquids in a sealed flask, which causes a gas to form and the flask to feel warm. If the total mass of the sealed flask and its contents was 250 grams before the reaction, what will the total mass be after the reaction is complete?

Less than 250 grams because some mass was converted to heat.

More than 250 grams because a gas was formed, which has more volume.

It is impossible to know without identifying the specific gas produced.

In a closed ecological system like a biodome, if the amount of carbon stored in plants and soil increases, what must be true about the amount of carbon in the atmosphere within that system?

It must have remained unchanged.

It was converted to pure oxygen.

The mass will decrease as the apple decomposes into simpler substances.

The mass will increase as fungi and bacteria grow and multiply.

The mass will stay exactly the same.

The mass will fluctuate but ultimately decrease as matter is destroyed.

The mass will increase because a gas is produced.

The mass will decrease because the sugar is consumed.

The mass will change depending on the room's air pressure.

The total amount of energy in a system always remains constant.

During any process in a closed system, the total amount of matter remains the same.

Matter can be converted into energy, but it cannot be destroyed.

Biological organisms can create new matter from energy to support their growth.