The answer is Liquid iron.
Answer: 
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
The balanced nuclear equation when the isotope Strontium-90 decays by Q- decay is :
A. good conductors - copper, aluminium
b. fair conductors - carbon,human body
c. insulator - paper, wood
<span>Ionic bonding between sodium and phosphate ions.</span>
Explanation:
Rutherford conducted an experiment in which he took a thin gold particle film on which he passes alpha- particles. He noticed that:
- Most of the alpha particles get through the film and can be detected by the detector.
- Around small portion of the alpha particle deflected at small angles.
- A very very few alpha particle (approximately 1 out of 1 million alpha particles) just retraced their path which means come back from the center.
He concluded that:
<u>Most of the space of the atom is empty and in the center of the atom , there is solid mass which is the cause of the alpha particles to come back. He gave the term nucleus to this solid mass.</u>
