The answer is D. Gold. Malleability, the ability for a material to be hammered or shaped into thin sheets, is a common property of metals. Among the choices, gold is the only metal. Also, gold is considered to be the most malleable metal.
The answer would be B, an electron because the proton is positive, neutron is neutral, and the nucleus is the center of the atom.
Although he did not do the experiment himself, he had come up with the idea of what to do and how to do it. I think that only Rutherford receiving credit is okay as the assistants did not do anything to contribute to the actual idea of the experiment.
For example, we credit the invention of the iPhone to Steve Jobs, the engineers of Apple, the designers, etc. - those with actual contributions to the invention and the ideas and not the Chinese factory workers - those who construct the iPhone itself.
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 3.
That is if an atom has 5 electrons in its outer shell, then it has 3 unpaired electrons.
As the outer shell have 1 s orbital too and that is fully filled and not available for bonding so it must have 3 unpaired electrons.
So the number of unpaired electrons in an atom that is having 5 electrons in its outer shell is 3.
