are all the question multiple choice?
Answer:
It changes size and shape
Explanation:
Proving Air Is Matter
One way to prove that air is made of matter is to blow up a balloon. Before you add air into the balloon, it is empty and shapeless. When you puff air into it, the balloon expands, so you know it is filled with something—air is taking up the space.
Answer:
a item dropping
Explanation:
KE is movement and PE is height. As it's falling it gets KE and falls downward giving it more KE and less PE
Zinc carbonate has the chemical formula : ZnCO3 and the equation for thermal decomposition is:
ZnCO3 .................> ZnO + CO2
1 mole of ZnCO3 produces one mole of ZnO
From the periodic table:
molar mass of zinc = 65.38 gm
molar mass of carbon = 12 gm
molar mass of oxygen = 16 gm
molar mass of ZnCO3 = 65.38 + 12 + 3(16) = 125.38 gm
molar mass of ZnO = 65.38 + 16 = 81.38 gm
125.38 gm of ZnCO3 produces 81.38 gm of ZnO, therefore:
mass of ZnO in 375 gm = (375 x 81.38) / 125.38 = 243.4 gm
Based on the above calculations, the correct answer is 243 grams
