A chemical reaction occurs when one or more change into one or more new substances called

How are energy and mass connected during the formation of an atom?

A student explained to the class that helium has 8 valence electrons because it is in group 18. Is the student correct? - The student is incorrect because helium has 2 valence electrons and it's in group 18 because the first energy level is full.

How many moles of methane (CH4) could be made from 4.6 moles of hydrogen?

How earth can be considered a system

The rate constant for this second‑order reaction is 0.670 M - 1 ⋅ s - 1 at 300 ∘ C. A ⟶ products How long, in seconds, would it take for the concentration of A to decrease from 0.690 M to 0.360 M?

How do you describe an Ionic Bond?

Calculate molality of a 2m aq solution of sodium chloride with density 1.35g/mol

One important factor in any chemical synthesis is the actual quantity of desired product obtained compared to the theoretical amount predicted on the basis of the stoichiometry of the reaction.

In the old west, a cowboy would put their ear on the railroad track to determine if a train was coming. Using this method, they could tell if the train was coming sooner than just listening for the train.

Is lead a mixture or pure substance? and is Paint a mixture or pure substance?