Yes, it is possible to decrease the resistance of a wire without changing the material it made out of. This is because, there are many factors which affect the resistance of a wire. These factors can be manipulated to change the resistance of the wire. The factors include: cross sectional area of the wire, length of the wire, temperature and the material of the wire. The other three factors can be manipulated to change the resistance of the wire without changing the material of the wire.
<u>Answer:</u> The fraction of atom's mass contributed by nucleus is 0.99
<u>Explanation:</u>
Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.
The isotopic symbol of Helium-4 atom is 
Number of electrons = 2
Number of protons = 2
Number of neutrons = 4 - 2 = 2
We are given:
Mass of He-4 atom = 
Mass of 1 electron = 
Calculating the mass contributed by the nucleus = 
Mass of the nucleus of He-4 atom = 
To calculate the fraction of atom's mass contributed by the nucleus, we use the equation:

Putting values in above equation, we get:

Hence, the fraction of atom's mass contributed by nucleus is 0.99
2.5 i believe i'll keep you updated i'm still trying to check my answers