Many drain cleaners are a mixture of sodium hydroxide and aluminum filings. When these two substances mix in water , they react to produce enough heat to melt the fat in a clogged drain. The bubbles produced are hydrogen gas. The complete reaction occurs in two steps: step 1:Al(s)+NaOH(aq) —> Al(OH)3(s)+Na(aq)
step 2: Na+(aq)+H2O —> Na2O(s)+H2(g)
a) Classify step 1 of the reaction as: addition, displacement, or decomposition.
b) Is this an endothermic or an exothermic reaction?
c) Balance each equation for each step of the reaction.

What enzyme is most important for dna replication and why?

Refer to this portion of a dichotomous key for fish identification to answer the question. 1. (a) has a single dorsal fin ® 5 (b) has a double dorsal fin ® 2 2. (a) one fin is spiny, the other is smooth ® 3 (b) one fin is not spiny or smooth ® 4 5. (a) has small fin on back near tail ® 6 (b) has no fin on back near tail ® 7 6. (a) has barbs near the mouth ® catfish (b) does not have barbs near the mouth ® 10 7. (a) tail is asymmetrical ® 8 (b) tail is symmetrical ® 9 10. (a) scales are small ® trout (b) scales are large ® whitefish what is the next step to complete to identify a fish that has a single dorsal fin, no fin on the back near the tail, and no barbs near the mouth? step 2 step 5 step 7 step 10

Why are common names a problem for scientist?