Answer: There are various indicators like litmus paper, phenolphthalein, universal indicator etc. that changes its colour to show the difference between acid and alkali.
Inorganic compounds make ionic bonds.
The answer is C due to the rain making contact with the iron it creates moisture which cause the iron to begin oxidizing which causes the iron to rust which is a chemical reaction then the blade which was once malleable because it was heat becomes harden and rust is created as I said before the physical aspect of the iron chances due to rust developing on it it's no longer has the luster it once had
Answer:
A barometer is an instrument used to measure air pressure and track weather systems. The most common unit of measurement used in barometers is the millibar (mb).
Explanation:
Having a pH of 6.3 for a kiddie pool would be considered as acidic. You need to increase this value to keep it safe for use. The safest pH level would be from 7.2 to 7.4. This would be safe for the skin of the one who uses the pool. Hope this answers the question.