As a substance changes fees from gas to liquid to solid:

A - the spacing between molecules increased

B - it's density generally increases

C - the spacing between molecules is not affected

D - it undergoes a chemical change

A beaker with saltwater was left uncovered and all water evaporated. If there are 0.505 g of NaCl left in a beaker that originally contained 75.0 mL of saltwater, what must have been the concentration of the original solution?

How many moles of O2 are needed to react with 24 moles of C2H6?

Why is activation energy required to start some reactions? to break the bonds of an endothermic reaction to overcome electron repulsion of an endothermic reaction to overcome electron repulsion of an exothermic reaction to provide sufficient energy

A 1.00 degree increased on the celsius scale is equivalent to a 1.80 degree increased on the fahrenheit scale. if a temperance increased by 48.0 C, what is the corresponding temperature increased on the faherheit scale

Which of the following reactions represents an exothermic reaction? A. NH3 (g) + 12.0 kcal → ½N2 (g) + 3/2H2 (g) B. CH4 + 2O2 → CO2 + 2H2O + 212,800 cal C. C + 2S → CS2, ΔH = 27,550 cal D. C (graphite) → C (diamond), ΔH = 0.45 kcal E.

Where do the heaviest elements in our solar system come from?

Four students presented different analogies to describe the formation of an ionic bond. Student A: A tug of war between seven middle school students and a high school student Student B: A small dog and a big dog tugging at a bone with equal strength

Chemical reactions occur when molecules or atoms collide so that the bonds between atoms break and new bonds form. breaking the bonds of the reactants requires energy; whereas, bond formation releases energy.

Calculate the volume of a 0.323-mol sample of a gas at 265 K and 0.900 atm.

What is the molar mass of the following substance : Cs2CO3