Answer:
At room temperature water, milk and lemon juice are liquid while oxygen is gas.
Step-by-step explanation:
The substances are liquid at room temperature if their normal melting points are lower than room temperature.
The melting point of oxygen is -218°C and boiling point is -189 °C that's why it is gas at room temperature.
Oxygen is diatomic gas O₂.
It is colorless and odor less.
The liquid and solid oxygen are pale blue in color.
It reactive with all other elements and form oxides except noble gases.
In diatomic form, under normal conditions oxygen is not harmful but in the from of ozone O₃ it is harmful if inhaled.
It is readily dissolve in a cold water.