Answer:
A) The catalyst makes lower energy pathways available.
Explanation:
A catalyst is a substance which speeds up a chemical reaction without itself being used in the reaction. Activation energy is the thresh hold energy which is required to initiate a chemical reaction. In the absence of catalyst, the activation energy is high therefore reactions are slower. But, presence of catalyst lowers the activation energy required to initiate the reaction as a result of which the reaction gets an alternate energy pathway to proceed which is responsible for speeding up the reaction.
It was the structure of DNA. Watson and Crick stole the credit from a woman whose name I can't remember, but basically she took really long exposure photographs (24 hours for some) and saw an X shape, which was the corresponding sign of a double helix. It was a pretty complicated method she was using and nobody had thought of using it for DNA research until then.
With Freezing.... the substance energy level decreases.
Freezing is endothermic and as such energy is lost to the environment
from the substance thus decreasing the energy level.
Answer:
Accumulation of trace elements, especially heavy metals, in the soil has potential to restrict the soil's function, cause toxicity to plants, and contaminate the food chain.
Explanation:
The three major rocks are igneous, sedimentary, and metamorphic
the two types of igneous rocks are diorite and gabbro
