A student seals 30 grams of sugar and 220 grams of water inside a jar. The jar and everything in it weigh 350 grams before stirring. After the sugar dissolves, what does the balance read?

The sealed jar of sugar water weighs exactly the same after stirring as it did before. What is the best explanation for that measurement?

The total weight of a closed jar of water stays the same after a spoonful of salt dissolves in it.

A class weighs 60 grams of iron filings and 90 grams of sand, then pours both into one covered cup and shakes it to mix them. What should the total weight of the iron filings and sand be now?

A shallow dish of salt water is left uncovered on a sunny windowsill for a week. The dish now weighs much less than before, and white crystals cover the bottom. What happened?

A sealed bottle of water and drink powder is weighed twice. Before mixing it reads 500 grams, and after mixing it reads 500 grams. What claim do these data support?

Vinegar is poured onto baking soda in an open cup on a balance. The mixture fizzes, and the balance reading slowly drops. Why does the reading go down?

The same amounts of vinegar and baking soda are mixed inside a sealed plastic bag on a balance. The bag puffs up and fizzes. What happens to the balance reading?

A team wants to find out whether the total weight changes when a powder dissolves in water. Which tool should they use to collect their data?

Ice cubes are sealed in a plastic bag that weighs 240 grams in all. The bag sits on the counter until every cube has melted. What does the bag weigh now?

Two groups test whether dissolving changes weight. One group keeps the lid on the jar and one group leaves it off. Why should every group keep the lid on?

Two substances together weigh 400 grams before they are combined in a closed container. The container is sealed and the substances are mixed together inside it. What happens to the total weight?

A capped bottle holding water plus a scoop of red drink powder weighs 480 grams. The bottle is shaken until the powder can no longer be seen. Predict the new weight.

Mia says dissolved salt still has weight. Rosa says dissolved salt has no weight. Which observation best supports Mia's claim?

Sugar dissolves faster in warm water than in cold water. Two sealed jars start at 400 grams each, one warm and one cold. After the sugar dissolves in both, how do their weights compare?

Soup is heated in a covered pot that stays on a balance. Steam rises inside, and drops form under the lid. What happens to the total weight of the pot and soup?

A student stirs 25 grams of sand into 175 grams of water, then filters it. She catches the water in a cup and lets the sand on the filter paper dry. What is the total weight of the sand and water she collects?

When a substance dissolves in water, its matter is still there as pieces too small to be seen.

A team mixes two substances in a sealed container and weighs it before and after, three times. Trial 1: 210 grams before, 210 grams after. Trial 2: 185 before, 185 after. Trial 3: 240 before, 240 after. What do these measurements show?

A student weighs an open beaker of water, lets it sit uncovered for two days, weighs it again, and reports that matter was destroyed. What is wrong with his investigation?