Question

to help categorize these patterns, scientists started referring to matter as having either a positive or negative charge, and they called matter with no charge neutral. but what was changing about the matter to produce positive or negative charge? this was a mystery until the 20th century. text chunk 1: write the main idea in your own words or images. (if you are not sure, reread and annotate.) j.j. thomson and cathode rays in the late 1800s, a scientist named j.j. thomson was especially interested in a phenomenon he observed in cathode ray tubes. cathode ray tubes are glass tubes filled with gas connected to a power source. the cathode ray tube creates a bright beam that moves from one end of the tube to the other. in fact, cathode rays look a lot like lightning! since the gas is very hard to energize, thomson suspected that something smaller than atoms might be causing the lightning - like beam. he designed several experiments to determine what was in these beams. those experiments are summarized in the table below. experiment: thomson held plates charged with static electricity next to the tube as the ray moved through the tube. observations: the beam bent toward positively charged plates and away from negatively charged plates. this happened no matter what gas was filling the tube.

Explanation:

The text first mentions the categorization of matter as positively - charged, negatively - charged, or neutral, and the mystery of what causes matter to have charge. Then it focuses on J.J. Thomson's interest in cathode - ray tubes in the late 1800s, his experiments with them, and the observations from those experiments.

Answer:

The main idea is the mystery of matter's charge and J.J. Thomson's experiments with cathode - ray tubes to understand the nature of the beams within them.