Answer:
Some elements are reactive because the outermost energy levels of their atoms are only partially filled. Therefore, these atoms can easily gain or lose electrons to form ions. The atoms of nonreactive elements have filled outermost energy levels
Explanation:
hope this answers your ?
A. Discovering a quick way to handle a new problem
Answer:
Weight and Mass !!!!!!
Explanation:
Galileo discovered that objects that are more dense, or have more mass, fall at a faster rate than less dense objects, due to this air resistance. A feather and brick dropped together. Air resistance causes the feather to fall more slowly.