<span>Phosphorus is about 0.099% in the Earth's crust. Among the elements in Group 15 in the periodic table, it is the most abundant. Also, it is the most dispersed element in nature. However, it does not occur as a free element. It occurs as a compound.</span>
The expectancy of how long a product will last divided by two!
It is called a watt and or wattage
An exothermic reaction releases heat. An endothermic reaction absorbs heat. Burning gas releases heat so it would be exothermic. Acid and water react heating the beaker would be exothermic because it releases heat from the reaction. Hope this helps! ;)