Answer:
(i) Protons, Neutrons
(ii) Mass number = 15
(iii) Atomic number = 12
(iv) Neutrons present in the atom = 17
(v) Nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si
Explanation:
(i) An atom is composed of three fundamental sub-particles: electrons, protons and neutrons. Electrons are found in orbits or energy levels some distance away from The nucleus of the atom. The nucleus of an atom contains the protons and neutrons which accounts for the mass of the atom.
(ii) The mass number of an atom of an element is the sum of the protons and neutrons present jn the nucleus of the atom.
The mass number of an atom of oxygen with proton or atomic number 8 and neutron number 7 is 8 + 7 = 15
(iii) Atomic number of an atom of an element is equal to the number of protons in the atom of the element.
Mass number = proton number + neutron number
Proton number = mass number - proton number
Proton number = 25 - 13 = 12
(iv) In the atom of sulfur represented bymthe symbol, the number in superscript is the mass number A, and the number in subscript is the atomic number Z.
Mass number = proton number + neutron number
Neutron number = Mass number - proton number
Neutron number = 33 - 16 = 17
(v) The nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si
Where the number in superscript is the mass number A, and the number in subscript is the atomic number Z.
