Give two reasons to justify- (a) water at room temperature is liquid. (b) an iron almirah is a solid at room temperature.
Answers
(a) 1.Water at room temperature is liquid due to the presence of hydrogen bond. These bonds hold water molecules together for small fractions of a second. Water molecules move continuously. In gaseous matter there is random movement.
2.Because of the hydrogen bonds, the water molecules come together they stick to one another for a small, but significant amount of time. This reduces the motion of them and holds them closer to one another. This property makes the water liquid at room temperature.
(b) An iron almirah is a solid at room temperature (25°C) because:
1.It has a definite and rigid shape and
2.Fixed volume like a solid at room temperature.
3.On applying external force the shape does not get deformed
Explanation:
1.Liquid has the following characteristics:
a.At room temperature, water has no shape but has a fixed volume i.e., it occupies the shape of the container in which it is kept.
b.At room temperature, water flows easily.
Answer:
(a) water persists as a liquid at room temperature since its melting point is lower than room temperature and its boiling point(100°c) is higher
similarly..
(1) A fixed volume is occupied by a fixed mass of water.
(2) At room temperature, water does not have a fixed shape and flow to fit the container shape
(b) Because its melting and boiling point are both above room temperature. In the same way
(1) An iron almirah is rigid and has a predetermined shape
(2) Metal have a relatively high density.