Easy question pls
which of the following substances is a fluid?
air
ice
sand
candles

The correct answer is A. Air

Explanation:

A fluid refers to a substance that flows or deforms due to external factors and other types of factors, in general terms, fluids include all liquids, gases, and substances in plasma state as in all of these molecules do not have a fixed arrangement but can move and therefore the substance can flow. On the other hand, solids are not fluids because due to the way molecules are organized and bonded in them they do not commonly deform or flow. This implies, the fluid substance is air, because this is a gas and thus a fluid, while others such as ice, sand, and candles are solids.

water   molecules stay close to each other through cohesion, the collective action of hydrogen bonds between water molecules. cohesion plants draw water upwards from the root through the stem's transport tubes (xylem) to the leaf. this transport occurs even in large trees and against gravity. transpiration, evaporation of water from plant leaves, creates a tension on water molecules being pulled up from the stem and roots.

water also has high (the attraction of one substance to another) properties because of its polar nature. adhesion of water molecules to plant cell walls counteract gravity while water is transported from roots to leaves.

water exhibits a very high surface tension when compared to other liquids. surface tension is a property of a liquid that holds the surface together and allows it to resist an external force. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water from the roots to the leaves of plants.

thus, cohesion, along with adhesion and surface tension creates a capillary action that keeps water molecules interacting and moving through the plants out to the leaf cells.

therefore, option d) is the correct answer.

explanation: