Question

An ion with mass number 56 contains 3 units of positive charge 30.4% more neutrons with electrons. Assign the symbol to this ion.

Answer 1

Hint: According to Dalton’s atomic theory, each element had a characteristic atomic mass. The law of proportions was easily explained by this theory. Measuring the atomic mass of an atom determined by the laws of chemical combinations and the compounds formed. The mass number of an atom is defined by the addition of the number of protons and neutrons.

Complete step by step solution:
-Let the unknown symbol of the element A, and is represented as from the given data = ${{^{56}}_{Z}}{{A}^{3+}}$
-Let the atomic number is Z and the number of protons is ‘p’.
-Given the unknown element has 3 units positive charge, then the number of electrons of the given element = p-3
-Number of neutrons, n= 30.4% more neutrons than electrons
-Then, n $=(p-3)+\dfrac{30.4}{100}(p-3)$
n= $(\dfrac{30.4}{100}+1)(p-3)$
n=1.304(p-3)
-Given element, the mass number is 56
-The mass number of an atom= number of protons + number of neutrons
56 = p+1.304(p-3)
56 = 2.304p – 3.912
59.912 = 2.304p
p = 26
-Thus, the number of protons = p =26
-Number of electrons = p – 3 = 26-3 = 23

Therefore, the symbol is ${{^{56}}_{26}}F{{e}^{3+}}$

Note: An Indian philosopher Maharishi kanad states that when we divide the matter will get smaller and smaller particles beyond a certain time further division not possible, these particles are known as paramanu. Scientists recognized the difference between elements and compounds by the end of the 18th century and naturally became interested in how elements combine then what happens after they combine.