1) A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure.

2) When you compress liquid together, the molecular forces  become very strong stopping it from being compressed very much.

The heat of fusion for water at 0 °C is approximately 334 joules (79.7 calories) per gram, and the heat of vaporization at 100 °C is about 2,250 joules (533 calories) per gram or $2.25 *10^6$ J/kg.

Since a liquid vaporises when molecules moves faster and farther apart but while increasing pressure, we apply an external force to hold molecules closer to each other. Hence, molecules will require more energy to overcome this resistance thus this increases boiling point of liquid. Hence, the boiling point of a liquid with the increase of pressure, increases.

Erlenmeyer flask $\rightarrow$ 

At room temperature, that is $25^o C$ and $1$atm, Mercury and Bromine both exist as liquids. Hence option A gives the correct pair.

Presence of hydrogen bonding in a liquid decreases its volatile nature. This is because due to hydrogen bonding, there is more association between the molecules and the tendency to go into gaseous phase decreases. Hence, $C _6H _6$ will be more volatile liquid since it has no hydrogen bonding.

As we know that $1g$ mole of any gas occupies as $22400ml$ of volume at STP

Among the given liquid glycerine is a viscous liquid and hence it was sucked with difficulty.

The properties of liquids are as follows:

Latent heat is the energy released or absorbed by a body during a constant temperature process. An example is a phase transition such as ice melting or water boiling. Heat absorbed during melting is called latent heat fusion.

The paper cup in which water is placed is having ignition temperature higher than the  boiling point of water, and water have high latent heat of vaporization. This is also possible that temperature provided to water does not exceed its boiling point. Hence, water can boil in paper cup without burning the cup.

As a liquid is heated at constant pressure, its temperature increases. This trend continues until the boiling point of the liquid is reached. No further rise in temperature of the liquid can be induced by heating due to increase in kinetic energy.

Ice provides more cooling effect than water at 273 K because of latent heat of fusion. Evaporation of a liquid causes cooling as the surface molecules take away heat to escape out. Increase of pressure lowers the separation between the particles of matter and brings them closer leading to change of state from gas to liquid and to solid.

Robert brown observed a weak solution of milk and later pollen grains in suspension with a high-powered microscope, and saw that the particles of milk and the pollen grains showed a violent and random motion. This motion was named as Browninan motion.

The shape of the meniscus observed when water and mercury are taken in two different capillary tubes is concave and convex respectively.

$Br _2$ and $Hg$ are in the liquid phase at $293 :K$.
$Cl _2$ and $F _2$ are gases.
$NH _4^+$ and $H _3O^+$ exist in aqueous solution.
$Fe$ and $Co$ are solids
Diamond and graphite are also solids.

Fluorine is most electronegative element so it forms stronger hydrogen bond which is the reason of stronger surface tension.So HF drops place maximum on the penny.

The rate of evaporation of water increases, if the atmospheric pressure is decreased during the extraction of colored components because atmospheric pressure is inversely proportional to evaporation. 

Evaporation is a surface phenomenon in which surface molecules of solution moves to the atmosphere.If atmospheric pressure is increased then due to external pressure molecules on the surface will not move to the atmosphere so if atmospheric pressure increases, a rate of evaporation decreases.

The boiling of water depends on the atmospheric pressure at that altitude. At high altitudes, the pressure is lower, so water can not boil at $100°$. As the altitude increases, the boiling point of water reduces.

Liquids and gases are similar in both shape and volume because they both have its' shape determined by its' surroundings. 

The boiling point of a liquid is the temperature at which vapour pressure becomes equal to the atmospheric pressure. Lower the atmospheric pressure, lower is the boiling point.

When metals are in liquids, they dissociate into ions and give away electrons. So, metallic liquids contain ions and mobile electrons.

Axons of nerve, striated muscle fibre, cilia all belong to bio-logical living systems.