The situation is fluid

Like a solid, a liquid has a constant volume; And like a gas, a liquid can flow from place to place. There are different liquids in our bodies - but they are all water-based solutions, so it is so important to drink water, so that we don't get dehydrated

Author: Zvi Atzmon, young Galileo
If there was a museum that displays the various materials in the world and it had a special shelf for materials that are liquids at normal temperature (room temperature), we would certainly find a bottle of water, bottles of different types of oil - kerosene, gasoline, acetone, alcohol, ether, acetic acid (acetic acid), Sulfuric acid - and two bottles with the only chemical elements that are liquid at room temperature - bromine and mercury.
As mentioned, bromine and mercury are chemical elements, while other liquids are liquids (water, acetone, alcohol, ether, etc.), and some of them are solutions that do not have a fixed composition, and in which some substances are mixed together (oils, oil, gasoline), but all of their components are liquids .

going with the flow

A liquid is a condensed flow. Flowing means a substance that can flow from place to place when there are pressure differences. Liquids and gases also flow. A condensed substance is a substance whose particles (the atoms or molecules) are close to each other and exert forces on each other, and it is almost impossible to compress them, that is, to squeeze them through external pressure; Liquids and solids are condensed substances. Hence liquids have properties in common with gases as well as solids. A liquid has a constant volume (at a certain temperature), but its shape is not constant, but changes depending on the vessel in which it is found.
The surface of a liquid has surface tension: thanks to mutual attraction (cohesion) between the molecules of the liquid, the outer surface of the liquid tends to have a minimal area. Thanks to its surface tension, objects heavier than it can be placed on its surface without them sinking (so, for example, paper clips made of metal can be carefully placed on the surface of the water, and insects can walk on the surface of the water without sinking in it). Despite the mutual attraction between the liquid particles, molecules can detach from its surface into the air - and the liquid will evaporate.
When the liquid is cooled enough - it freezes, becomes solid. When heated enough - it boils and becomes a gas (provided the substance is stable and does not disintegrate during heating). The boiling point of a liquid decreases when the external pressure on its surface is small. And vice versa - at high pressure, the boiling point rises, and thus it is possible to condense gas at a relatively high temperature. For example, the gas used for cooking is in metal containers (gas cylinders) at high pressure, and is stored in them as a liquid called "condensed hydrocarbon gas" (LPG).

body fluids
There are many fluids in our body: the blood is a fluid (and more precisely: liquid tissue because it also contains blood cells), and the plasma of the blood is a fluid, as well as the saliva and other digestive juices - the stomach juice, bile juice, and also the urine, sweat and other fluids that are in the body. All these liquids are aqueous solutions: what makes them liquids is one liquid substance - the water. Fortunately, our body does not contain liquids such as bromine, mercury, ether and gasoline.
As mentioned, all body fluids are aqueous solutions. The blood contains blood cells (red and white), and these "float" in a light yellow aqueous solution - the plasma of the blood. The blood flows through the blood vessels thanks to the heartbeat. Since the blood is a liquid tissue, there is a danger of losing blood when it leaves the blood vessels, and this condition is called hemorrhage. Most of the blood plasma is made of water, in which salt and other minerals are dissolved, as well as glucose (blood sugar), nutrients absorbed in the intestines and important proteins.
The urine is the filtering product of the blood: the kidneys remove into the urine what is in the blood and the body does not need it. Therefore, the amount of urine and its composition change: if you drink a lot of water, a lot of water reaches the blood, and the kidneys transfer the excess water to the urine and the amount of urine is increased; This is a normal situation. If you eat salty things (preferably not), the kidneys remove the excess salt from the blood into the urine, and then the urine contains more salt.
The sweat is a solution that contains mainly water, a little salt and other substances. The sweat glands in the skin produce sweat from water and are little dissolved by the blood reaching them.

risk of dehydration

 
On hot days or when you exert yourself and the body produces heat - sweat is secreted. As the sweat evaporates into the air, our skin cools and cools the body. If the amount of water we consume is less than the amount of water we lose (in urine, sweat, breathing and other ways), the amount of water in the body is small, and the volume of body fluids is small. This is a dangerous condition, and it is called dehydration or fluid loss. The condition manifests itself in a bad feeling and poor general functioning, and may even end in death. In a state of fluid loss, the lost fluids are water, so it is important to add water to the body, and not other fluids. Add water to drink, and when the situation is serious - through the infusion of a suitable aqueous solution into the blood. If you drink, you don't get dehydrated!

The article appeared in the July issue of Young Galileo – Monthly for curious children

Want to read more? for receiving Young Galileo magazine as a gift

Visit our Facebook page