What kind of decay must have occurred given the reaction below?

These are two questions and two complete answers.

Answers:

Explanation:

A) Question #5.

The figure shows that the parent nuclide is and the daughter nuclide is

A mass number balance and an atomic number balance show the features of the radiation emitted.

a) Mass number balance:

The mass number is the superscript to the left of the chemical symbol and is the amount of protons and neutrons in the nucleus of the atom.

Hence, the mass number of the unknown emitted particle is 4.

b) Atomic number balance.

The atomic number is the subscript to the left of the chemical symbol and is the number of protons in the nucleus of the atom.

Hence, the atomic number (number of protons) of the unknown emitted particle is 2.

Conclusion: the emitted particle is a particle with 2 protons and 2 neutrons, which is a nucleus of helium, ⁴₂He, also called alpha particle, and the reaction is named alpha decay.

B) Question #6

Again, a mass number balance and an atomic number balance will tell which element is the missing product in the reaction.

The reaction is:

a) Atomic number balance:

Hence, the missing product has atomic number 50 which permits to tell that it is an atom of tin (Sn).

b) Mass number balance:

Which means that the missing product has a 132 neutrons and protons:

The symbol of this atom is:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%