Check for endorsements by celebrities of home-improvement shows.
Answer is: acid-base indicator or pH indicators.
Acid-base indicators are usually weak acids or bases and they are chemical<span> detectors for hydrogen or hydronium cations.</span>
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄). Phenolphthalein is <span>colorless in </span>acidic<span> solutions and pink in </span>basic<span> solutions.
Another example is m</span><span>ethyl orange. It is red colour in acidic solutions and yellow colour in basic solutions.</span>
The answer is lower. when there’s a lower temperature the molecules will be moving at a lower speed. a lower speed means less thermal energy.
I think O and Cl will form covalent bonds since they are both non-metals and don't have a large enough difference in electronegativities to create an ionic bond.
I hope this helps. Let me know if anything is unclear.