Answer:
Is this math? Cause as a fourth grader, I can do Algebra, but not this.
Explanation:
25 gigaseconds is equal to 2,500,000,000,000 centiseconds
Answer: Hydrogen molecules will have greatest average speed.
Explanation:
The formula for average speed is :

R = gas constant
T = temperature
M = Molecular Mass
Now putting all the values:



Thus average speed of hydrogen is 8 times the average speed of oxygen. Thus hydrogen molecules will have greatest average speed
I believe the correct answer from the choices listed above is the second option. The pair of elements that is most likely to chemically combine and form ionic bonds would be <span>lithium and chlorine. Lithium is metal and chlorine is nonmetal which as a compound forms ionic bonds. Hope this answers the question.</span>
The substance that can be broken down by chemical means from the choices given is CO (Carbon monoxide). Carbon monoxide is a compound made up of carbon and oxygen and can therefore be broken by chemical means.