I would say the answer is D
Paint samples received by forensic laboratories are usually in the form of small chips or smears. Infrared (IR) spectroscopy is one of the most commonly used tools available for the analysis of these types of samples and serves as a staple comparative technique in the assessment of whether or not a questioned sample could have come from a suspected object
The most direct way to probe the vibrational frequencies of a molecule is through infrared spectroscopy. This is because vibrational transitions typically require an amount of energy that corresponds to the infrared region of the spectrum. Raman spectroscopy, which typically uses visible light, can also be used to directly measure vibration frequencies.
Explanation:
An alpha particles is basically a helium nucleus and it contains 2 protons and 2 neutrons.
Symbol of an alpha particle is
. Whereas a neutron is represented by a symbol
, that is, it has zero protons and only 1 neutron.
Therefore, reaction equation when an aluminum- nuclide transforms into a phosphorus- nuclide by absorbing an alpha particle and emitting a neutron is as follows.

As you go down a group on the periodic table, atomic radii tend to increase because elements with larger atomic numbers have more occupied electron levels which take up more space surrounding the nucleus.
I hope this helps.
I think it is "Known".
Radioactive decay is measured using a formula where the half-life <span>of an isotope is the time it takes for the original nuclei to decay half of its original amount.</span>