A Levels Physics

Four nuclei are represented below.
25 G
28
14
25
12M
24
13 Q
Which statement about these nuclei is correct?
A An uncharged atom of element Q has 24 orbital electrons.
B Nucleus M could transform into Q by emitting a beta particle.
C Nuclei G and M are isotopes of the same element.
D When E absorbs a neutron and then emits an alpha particle, nucleus E transforms into M.


Choice D is correct because:

Absorption of a neutron by E: 14 E 28 + 0 n 1 → 14 X 29

Emission of alpha particle by X: 14 X 29 → 12 Y 25 + 2 α 4

12 Y 25 = 12 M 25, therefore nucleus E can transform into M when E absorbs a neutron & then emits an alpha particle.

Choice A is incorrect because:

An uncharged atom of element Q has 13 (not 24) orbital electrons.

Choice B is incorrect because:

Beta particle emission of nucleus M: 12 M 25 → 13 X 25 + β− + ν̅  + energy.

13 X 25 ≠ 13 Q 24, therefore nucleus M will not transform into Q by emitting a beta particle.

Choice C is incorrect because:

Nuclei G & M are not isotopes of the same element because they do not have the same number of protons.

Nuclear Fusion and Fission, Radioactive Decay | 2014 - M/J - 9702/13 | Q40