If you were going to build a system to check the effectiveness of automobile catalytic converters on cars, what substances would you want to look for in the car exhaust?

Oxides of nitrogen and hydrocarbon

Explanation:

An automobile catalytic converter is a substance that catalyses redox reactions that convert toxic gases emanating from an automobile engine to less toxic gases.

The substance work by converting carbon monoxide (CO) and hydrocarbons to carbon dioxide and water and oxides of nitrogen to nitrogen and oxygen gas respectively.

Hence, in order to check the effectiveness of a catalytic converter, unburned hydrocarbon and oxides of nitrogen are substances to watch out for in the car exhaust. None of these gases should be found in an exhaust with effective catalytic converter and vice versa.

the tides are influenced by both the moon and the sun, it's easy to see that when the sun lines up with the moon and the earth, as during a new moon or full moon, the tidal effect is increased. these are known as spring tides, named not for the season, but for the fact that the water "springs" higher than normal. on the other hand, if the sun and the moon are 90 degrees apart in relation to an observer on earth as during the first quarter moon or third quarter moon, then high tides are not as high as they normally would be. this is because despite its greater distance, the sun's mass allows it to exert enough gravitational force on the oceans that it can negate some of the effects of the moon's pull. this phenomenon of lower high tides is called a neap tide. if you need more information on this topic visit moonconnection.com.