The graph shows data from ice cores. What has happened to carbon dioxide levels over time?
Atmospheric CO, (ppm)
Atmospheric Carbon Dioxide
350 from Law Dome Ice Cores
340
330
320
310-
300
290
280
1000
1200
1800
2000
1400 1600
Year (AD)
A. They have increased dramatically recently
B. They have gone up and down with no general trend.
C. They have decreased dramatically recently.
D. They have remained flat and steady.
Apex

what subject is this

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

what are the awnser choices? i mean, without choices, it is an incompleat