The human heart
an heart is an organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes
The heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, as well as assists in the removal of metabolic wastes.
Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
The alveoli are adapted to make gas exchange in lungs happen easily and efficiently. Here are some features of the alveoli that allow this: they give the lungs a really big surface area. they have moist, thin walls (just one cell thick)
Group one metals are very reactive metals, they can react with the tiniest water molecules in air. That’s reason why they have to be stored under oil. Also they bare the vertical column on the left hand side of the periodic table. The following metals are in group one:
lithium=Li
sodium=Na
potassium=k
robidium=Rb
cisium=cs
francium=Fr
when lithium reacts with water it flows and fizzes until it becomes smaller and disapers.
lithium +water=lithium hydroxide+hydrogen
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