Atomic Nuclei Composition and Nuclear Concepts Quiz

X: 12, Y: 14

Isotopes

False

<p>False</p> Signup and view all the answers

<p>Atomic Nucleus</p> Signup and view all the answers

<p>No</p> Signup and view all the answers

<p>Thomson's model couldn't explain the stability of an atom or the arrangement of electrons within it.</p> Signup and view all the answers

<p>Rutherford's model failed to explain why electrons, with a negative charge, do not spiral into the positively charged nucleus.</p> Signup and view all the answers

<p>Bohr's model introduced the concept of quantized electron orbits around the nucleus, where electrons can only occupy certain fixed energy levels.</p> Signup and view all the answers

<p>The first shell can hold up to 2 electrons, the second up to 8, and the third up to 8 as well.</p> Signup and view all the answers

<p>(i) The atomic number is the number of protons in an atom's nucleus. (ii) The mass number is the sum of protons and neutrons in an atom. (iii) Isotopes are atoms of the same element with different mass numbers. (iv) Isobars are atoms with the same mass number but different atomic numbers.</p> Signup and view all the answers

<p>The average atomic mass of bromine = (0.497 * 79 + 0.503 * 81) u.</p> Signup and view all the answers

<p>Chlorine: 1, Sulphur: 2, Magnesium: 2</p> Signup and view all the answers

<p>8</p> Signup and view all the answers

<p>Atomic number is the number of protons in the nucleus of an atom. It determines the identity of the element and is unique for each element.</p> Signup and view all the answers

<p>The mass number is the sum of protons and neutrons in the nucleus. It depends on the composition of the nucleus.</p> Signup and view all the answers

<p>Atoms of the same element have the same number of protons, which determines the atomic number.</p> Signup and view all the answers

<p>The mass of an atom is primarily due to the protons and neutrons in its nucleus. Electrons contribute very little to the mass.</p> Signup and view all the answers