Is matter conserved when there is the same amount before and after a change?

The best solution for preventing harm to people and pets from severe hurricanes involves determining and warning residents about what

The diagrams show objects’ gravitational pull toward each other. which statement describes the relationship between diagram x and y? gravity attracts only larger objects toward one another. gravity attracts larger objects only if they are close to one another. if the masses of the objects increase, then the force between them also increases. if distance between the objects increases, then the amount of force also increases.

How many moles are in 43.9 l of oxygen