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:
1.402 * 10^2.
Explanation:
There are 3 digits before the decimal point so the exponent is 2.
Answer:
It is called a salt bridge
