Answer:
It is less dense than oxygen gas.
Explanation:
Density is a physical property. Reactivity, flammability, and acid compounds are all chemical properties.
Hope that helps.
Answer:
A. Substance E
A. Substance C
A. Substance A
Explanation:
Given that:
At 4 °C, Substance E has a vapor pressure of 86. torr and Substance F has a vapor pressure of 136. torr
Which has a higher boiling point?
A. Substance E
B. Substance F
C. Neither,EandF have the same boiling point
The vapor pressure varies inversely proportional to the boiling point.

Therefore, the lower the vapor pressure, the higher the boiling point.
At 4°C, Substance E with a lower vapor pressure of 86. torr will have a higher boiling point from the given information.
2.
Recall that :

therefore, the lower the enthalpy of vaporization, the higher the vapor pressure at any given temperature.
Given that:
Substance C has an enthalpy of vaporization smaller than that of substance D. Then, substance C has a higher vapor pressure.
3.
We've earlier said that:
The vapor pressure varies inversely proportional to the boiling point.

Therefore, the lower the vapor pressure, the higher the boiling point.
As such, Substance A will have a higher boiling point.
Answer:
As water freezes, a crystalline structure preserved by hydrogen bonding is formed by water molecules. Less dense than liquid water is solid water, or ice. Ice is less dense than water since molecules are pulled farther apart by the direction of hydrogen bonds, which decreases density.
Explanation:
P is momentum f is force and m is mass