Answer:
Here's what I get.
Explanation:
Quinine contains phosphors, substances that glow when they are hit with certain wavelengths of light.
The phosphors in quinine absorb UV light, which is invisible to our eyes.
Electrons in the phosphors absorb the UV energy and are excited to higher energy levels.
When the electrons drop back to lower energy levels, they emit some of this energy as a glowing blue visible light.
The number of grams of radon 222 did it have 15.2 ago was 49.6 grams( answer C)
<u>calculation</u>
- calculate the number of half life it has covered from 15.2 days to 3.8 days
that is divide 15.2/ 3.8 = 4 half life
- half life is time taken for a radio activity of a specified isotope to fall to half its original mass
therefore 3.8 days ago it was 3.1 x2 = 6.2 grams
7.6 days ago it was 6.2 x2 = 12.4 grams
11.4 days ago it was 12.4 x2= 24.8 grams
15.2 days ago it was 24.8 x2=49.6 grams
Other natural material such as clay, wood, and stones can be changed into art.
Clay is pliable and is very easy to be molded into different shapes and sizes.
Wood can easily carved into different shapes, also different patterns can be easily etched on wood.
Stones of different variety and from different geological sources are painstakingly converted into statues or portraits of different life forms and scenery.
Covalent for the first one