A chemical reaction is a process in which one or more substances are changed into new substances.
An example of a chemical reaction is when metal rusts.
The fulcrum is the point in any mechanical device where the moment due to weights is zero.
(Weight 1 x distance 1) - (weight 2 x distance 2) = 0
(1.7 Kg x 1.5 m ) - (weight 2 x 1.2 m) = 0
weight 2 = (1.7 Kg x 1.5 m ) / 1.2 m
= 2.1 Kg
Answer:
carbon and three oxygen atoms
I would say energy myself, and this is because energy plays a key role in all of these. With trophic levels energy is being transferred amongst the levels. Food chain's is a map of how the energy is passed along the chain. Food web is a web of how energy is transferred, and this is why I would say energy is a keyword.