<u>Chemical</u>. The copper atoms form new chemical bonds with atoms in the air.
Answer: 5.5
Explanation: Strontium titanate is both much denser (specific gravity 4.88 for natural, 5.13 for synthetic) and much softer (Mohs hardness 5.5 for synthetic, 6–6.5 for natural) than diamond.
It is B nevermind I thought it was c but it wasn't.
Answer:
please mark my answer brainliest
Explanation:
its carbon monoxide
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