Answer:The environmental problems directly related to energy production and Electricity is a secondary energy source that is generated producedfrom primary energy sources:
hope that helps im new so have a good day (:
Explanation:
Classification of the Elements. The next thing in our review is to classify the elements into three groups. These three groups are: metals, nonmetals, and inert gases. Let's look at where these groups are located on the periodic table and correlate them with the ability to lose and gain electrons.
The atomic mass of element is the weighted average atomic mass of the element with respect to the abundance of the isotopes of that element
atomic mass is the sum of the products of the mass of isotopes by their percentage abundance
atomic mass = 15.000 amu x 5.000 % + 16.000 amu x 95.000 %
= 0.7500 + 15.200
atomic mass of element is therefore 15.950
The answer is B.
occur gradually over millions of years.