Question

All elements are the same everywhere and all atoms of the same element are also the same.
Suppose you make contact with an alien race who want to share their scientific knowledge with you.
They have elements too, but they classify them by the number of neutrally charged particles.
They present you with their element, "Gacainium", which has 117 neutrally charged particles.
Taking a sample back to the lab, you find that the mass number of the element Gacainium to be 195.

What is the Earth equivalent of this element the aliens have presented to you?

please helpp ! own words

Answer 1

The periodic table you're familiar with lists atoms by their atomic number, which is the number of protons an atom has. The atomic number is identified as "Z."

We know that the atomic mass of an element is given as neutrons + protons in unified atomic mass units. Atomic mass is identified as "A" and the number of neutrons is identified as "N." Remember, that all elements have isotopes, which have differing number of neutrons. The mass value listed on the periodic table is the average mass of the element considering all the naturally occurring isotopes. However, the given mass is typically very close (with 1%) to the whole number "A" as defined above.

It follows that if mass (A) is the sum of the number of neutrons and protons in an atom of a given element that \[A = Z + N\]In the problem, we are given the number of "neutrally charge particles," which are the neutrons (N), and the atomic mass of the element. We can readily solve for Z is the above equation. Remember the Z is the atomic number, which is easily looked up on the periodic table to determine the element.