Answer:
Noble gases are nonreactive elements.
Explanation:
We call Group 18 of the Periodic Table "Noble gases" because they are inert gases. They do not like to bond with other elements.
The reason why is because their outermost shell for electrons is full. These electrons, called valence electrons, are are completely maxed out and therefore makes the element stable. This in turn makes it so that it doesn't really bond with other elements.
Answer:
The correct answer is - 43%.
Explanation: The increase in CO2 between these two suggested periods is approximately 43%. Even though it is a natural process that the CO2 levels vary in the atmosphere, still this is not the same case nowadays. Nowadays, or rather in the past few decades, apart from the natural increase of CO2 in the atmosphere, it has seen a much more increased levels because of the human activity. The industrial facilities and the vehicles, the cutting of the forests and burning the wood (there's both release of CO2 from the burning of the trees and loss of natural accumulator of the CO2), are just some of the more important human activities that contribute to a significant rise in the CO2 levels.
0.078 times the orbital radius r of the earth around our sun is the exoplanet's orbital radius around its sun.
Answer: Option B
<u>Explanation:</u>
Given that planet is revolving around the earth so from the statement of centrifugal force, we know that any
The orbit’s period is given by,
Where,
= Earth’s period
= planet’s period
= sun’s mass
= earth’s radius
Now,
As, planet mass is equal to 0.7 times the sun mass, so
Taking the ratios of both equation, we get,
Given 
and 
