Which factors would decrease the rate of a reaction? i. lowering the temperature ii. increasing the concentration of reactants iii. adding a catalyst

Can someone me with questions 15 to 17 plz.

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

Ahydrogen atom has 1 electron. how many bonds can hydrogen form? a) 1 b) 2 c) 3 d) 4 e) 5