Because the copper roofs, have been outside for a while and oxidization has occurred.
When metals become oxidized they rust, but when copper becomes oxidized, it turns greenish.
So copper roofs oxidize and turn green from being outside and a copper square doesn’t if it’s inside.
<u>Answer:</u> The final volume of the gas comes out to be 4 L.
<u>Explanation:</u>
To calculate the volume with changing pressure, we use the equation given by Boyle's law.
This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
Mathematically,
(At constant temperature and number of moles)
The equation given by this law is:

where,
are initial pressure and volume.
are final pressure and volume.
We are given:

Putting values in above equation, we get:

Hence, the final volume of the gas will be 4 L.
Answer:
a motor that requires no energy input once it is running
Answer:
if the dependent and independent variable go up its direct but if one of them goes up and another goes down its indirect
Explanation:
for example the more mass an object has the less speed it has that's indirect but the less salt you add to water the less time you have to wait for it to boil
i hope this was useful
Where are the substances?