<span>Its b.aluminum
I hope this helps and sorry if I am wrong </span>
Answer:In a physical change, atoms are not rearranged and the matter's physical and chemical properties are unchanged. Chemical changes, on the other hand, rearrange the atoms of matter in new combinations, resulting in matter with new physical and chemical properties.
Explanation:
easy
Number of atom in one mole = 6.022 × 10²³
So, in 3.5 moles, it would be: = 6.022 × 10²³ * 3.5 = 2.1 × 10²⁴
In short, Your Answer would be 2.1 × 10²⁴ atoms
Hope this helps!
<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.