At the start of the coal combustion experiment, the combined mass of the coal and oxygen reactants was 100 grams. At the end of the coal combustion experiment, the mass of the sample was 100 grams. Why does the scale showing the mass at the end of the reaction give a mass of 100 grams, when there is only a small amount of solid particles remaining on the scale?

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

Can someone me with these questions plz.

When the speed of the bottle is 2 m/s, the average maximum height of the beanbag is m.