Experiments test the scientists' ideas.
Astronomers use chemical signatures to determine<span> the age and .... </span>Gas<span> mixtures that contain more than </span>4<span>% hydrogen in </span>air<span> are potentially explosive. ... water vapor, </span>carbon dioxide<span>, and several other </span><span>gases</span>
Answer:
hello, the answer is polygenic:)
The answer is a , as aluminium has 13 protons and electrons .