For the first question the answer is
The "s" orbital can only hold a maximum of two electrons. ... Elements in the each group have the same number of valence electrons. Why is hydrogen set apart by itself? Hydrogen does not belong to a single group b/c it can be considered an alkali metal, but it is also a gas.
It is true that human impact on one system leads to changes in more of Earth’s systems.
Answer: Option A
<u>Explanation:</u>
Human impact had created large impacts on Earth’s systems. The pollution in air, deforestation, dumping of lakes lead to several changes in environment. Also emission of carbon, methane and other hazardous gases from several manufacturing unit effect the environment.
Along with this, increase in usage of non-renewable fuels and release of CFC's emitted from AC’s, fridge lead to elimination of ozone layer making the environment open to direct UV radiation. So yes, it is true that human impact on one system leads to changes in more of Earth’s systems.
A. Archilles ! Hope this helped :)!
I think it is Global warming
