Answer:
Covalent bonds form when two atoms share valence electrons,
while Van der Waals forces cause an attraction between nonpolar
molecules
Explanation:
A covalent bond is said to be formed when two atoms of the same or different elements share electrons. In an ordinary covalent bond, each bonding atom contributes one valence electron while in a dative covalent bond only one of the bonding atoms provides the shared pair of electrons.
Van Der Waals forces is the major intermolecular interaction between non polar compounds. Van Der Waals forces " are caused by correlations in the fluctuating polarizations of nearby particles"(Wikipedia).
Answer:
The answer is D
Explanation:
Because as the energy travels from one animal to the other the energy decreases. For example a gazelle eats the grass right? And then a lion eats the eats the gazelle. The gazelle got energy from the grass it's body already used some so when it's eaten the lion only gets what energy the gazelle has leftover
One big reason for this is because individuals of the same species often have to fight over shared resources (this means shared food and shared environment).
Because they fight over a limited amount of space and food, competition between individuals within one species can be present and very tough.
On the other hand, having members of different species also possibly means different territories and different food sources. A lion has no quarrel with dolphins, while it can have a lot of fights with lions from different prides (large group of lions).
They are both important because mechanical has to do with physical - cause mechanical means physical, so chewing your mouth is physical (you break your food into smaller pieces physically). And then chemical digestion is when food and saliva mix together. They happen when breaking down food into nutrients - enzymes. Enzymes are important for that process, because they make a nutrient.
Hope this helps!!
Sweating is the body's way of cooling itself. If you did not sweat, you could overheat the body and collapse from heat exhaustion.