Answer: 
Explanation:
Engineering notation : It is the representation of expressing the numbers that are too big or too small and are represented in the decimal form times 10 raise to the power. It is similar to the scientific notation but in engineering notation, the powers of ten are always multiples of 3.
The engineering notation written in the form:
where,
a = the number which is greater than 0 and less than 999
b = an integer multiple of 3
Now converting the given value of 2,469,100 into engineering notation, we get
Hence, the correct answer is, 
<u>Question in English : </u>
<span>
<em>An atom X has 8 neutrons and its atomic number equals 8. Knowing that this atom is isotopes of Y, which has mass number 18, answer: What is the number of neutrons in atom Y?</em>
</span><span><u>Answer :</u>
</span>Isotopes are defined as the atoms which have same number of
protons but different number of neutrons of same element. Since the proton
number is same, the atomic number also same. Hence the atomic number of Y is 8.
Mass number = atomic number + neutron number
18 = 8 + neutron number
Neutron number = 10
Hence, there are 10 neutrons in Y.
They will repeal(that is the correct answer to the question)<
He is the only one that includes only mollecules
<span>The correct answer would be: 4 oxygen atoms</span>