Precision refers to the closeness of two or more measurements to each other. Using the example above, if you weigh a given substance five times, and get 3.2 kg each time, then your measurement is very precise. Therefore, your answer is (B)
Answer:
-a nonmetal is a substance that lacks the characteristics of a metal.
-Seventeen elements are generally classified as nonmetals: most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).
Answer: combustion
Explanation:
Combustion reactions can be identified by looking at the reactants and the products.
Usually, the reactants will be a hydrocarbon and oxygen. And the products will be CO2 and H2O
Answer:
Your statement is right.
Explanation:
When fuels are burned in vehicle engines, high temperatures are produced. At this high temperature, nitrogen and oxygen from the air combine with each other to produce nitrogen monoxide (NO). When this nitrogen monoxide is released in the air from vehicle exhaust systems, it combines with oxygen present in the air to form nitrogen dioxide (NO2).
