Water molecules stay close to each other due to hydrogen bonding. When water is in a liquid state, hydrogen bonds frequently form, break, and re-form. This causes many water molecules to be bonded together. Hydrogen bonds collectively hold water together, and this is called cohesion. Cohesion contributes to the transport of water/dissolved nutrients against gravity in plants. Water evaporates from leaves, and then hydrogen bonds cause water molecules that are leaving the veins to tug on molecules farther down. This causes the upward pull to be transmitted through the water conducting cells all the way down to the roots.
Adhesion is a very similar property of water. It is the clinging of one substance to another. Adhesion also plays a role in the transport of water/dissolved nutrients in plants. Adhesion of water to the walls of cells helps to counter the downward pull of gravity.
Water also has a greater surface tension than most liquids. Surface tension is a measure of how difficult it is to stretch or break the surface of a liquid. The interface between water and air contains an ordered arrangement of water molecules that are hydrogen-bonded to each other as well as the water below. This causes water to behave as if it is covered with an invisible film. Some animals can even stand, walk, or run on water without breaking the surface because of its high surface tension.
Adhesion is a very similar property of water. It is the clinging of one substance to another. Adhesion also plays a role in the transport of water/dissolved nutrients in plants. Adhesion of water to the walls of cells helps to counter the downward pull of gravity.
Water also has a greater surface tension than most liquids. Surface tension is a measure of how difficult it is to stretch or break the surface of a liquid. The interface between water and air contains an ordered arrangement of water molecules that are hydrogen-bonded to each other as well as the water below. This causes water to behave as if it is covered with an invisible film. Some animals can even stand, walk, or run on water without breaking the surface because of its high surface tension.
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