Hot air balloons have hot air inside them, which is less dense as the air around it. Thus it rises. A cold air balloon would sink because the air would be more dense than the air around it. Also, the balloon’s volume would vary in size depending on the weight of the balloon.
The answer is (2) higher vapor pressure and weaker intermolecular forces. Propanone has a lower boiling point, so it is more volatile than water. Propanone's vapor pressure is, therefore, higher than that of water at 50 degrees Celsius. Propanone is more volatile due to the fact that the intermolecular forces that hold its molecuels together are not as strong as those that hold together molecules of water. Since the IMFs are weaker, it takes less thermal energy to break individual molecules free of each other.
because it can influence how frequently and sufficiently the particles collide depending on the space it has to do so, for example a large surface area would be have a slower rate of reaction and a lower temperature. (the rate of reaction in terms of concentration, it is diffused from high to low)
Answer:
quartz (SiO2)n
Explanation:
Melting point is defined as the temperature or point at which the substances change its state from solid to liquid.
Quartz (SiO2)n has high melting point than O2 because Quartz (SiO2)n is found in the form of hard, crystalline mineral that is made up of silicon and oxygen atoms having strong covalent bonds between all the atoms. So, a lot of energy is required to break the bond between the atoms and it has a high melting point.
Hence, the correct answer is quartz (SiO2)n.
Answer : The vapor pressure of bromine at 
is 0.1448 atm.
Explanation :
The Clausius- Clapeyron equation is :
where,
= vapor pressure of bromine at = ?
= vapor pressure of propane at normal boiling point = 1 atm
= temperature of propane = 
= normal boiling point of bromine = 
= heat of vaporization = 30.91 kJ/mole = 30910 J/mole
R = universal constant = 8.314 J/K.mole
Now put all the given values in the above formula, we get:
Hence, the vapor pressure of bromine at is 0.1448 atm.
