Which two types of clouds indicate fair weather? A: Cirrus and Cumulus
B: Cirrus and Stratus
C: Cumulus and Stratus
D: Cumulus and Nimbostratus
How does temperature affect the formation of clouds?
A: Water vapor in the cool air condenses into tiny droplets of water, forming clouds.
B: Water vapor in the warm air condenses into tiny droplets of water, forming clouds.
C: Cool air combines with warm air to form clouds.
D: Water vapor in the cool air evaporates from the hydrosphere to form clouds.

astronomers such as edwin hubble.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

gasoline is a mixture. it contains several different kinds of compounds that can be present in a variety of ratios.