Recent content by AryaUnderfoot

Hi! I'm a recent graduate who majored in aquatic biology and minored in computer science. During my degree and an internship, I found out that the practical parts of biology does not quite appeal to me, but when I was briefly introduced to the more theoretical aspect, math modelling for wildlife...

Homework Statement Archeologists removed some charcoal from a Native American campfire, burned it in O2, and bubbled the CO2 formed into Ca(OH)2 solution (limewater). The CaCO3 that precipitated was filtered and dried. If 4.58 g of the CaCO3 had a radioactivity of 3.2 d/min, how long ago was...

Ah, my bad. I forgot the significant number behind the values..I got it now. Thanks! And also sorry for late reply ^^

Homework Statement The mass of a helium-4 atom is 6.64648310224 g, and each of its two electrons has a mass of 9.10939310228 g. What fraction of this atom’s mass is contributed by its nucleus? Homework Equations fraction of mass = mass of nucleus/mass of atom The Attempt at a Solution I...

About A. victoria. I mean, if we can see the green ring under normal circumstances, why would we need a fluorescence microscope? And I read that they don't usually produce the ring, unless they are disturbed? I couldn't quite grasp that

Ahh I never knew! What does this sensor call? I tried to google it but I can't find its principle. I'm interested to know if we can (or already did?) fit that in the fluorescent or uv microscope to observe the patterns that are normally invisible to us.

Umm, my English is not good..but I'll try. So there were 2 photos of the same evening primrose. One showed it as the way we normal human will see it--yellow and without pattern; the other one showed it as the way bees see it--with special pattern. It is known that bees can see into UV range...

I understand that the wavelength of UV is too short to be absorbed by our cone cells, but I've came across 2 photos of evening primrose, which to our eyes are a dull yellow, but to insects (can see the UV light), it has a special pattern. My question is, I thought we're not able to see it. but...

Can we see it under normal circumstances? Or do we need the help of special UV light source to see it? I've read that Aequorea victoria can emit bioluminescence with a ring of green dots at the margin of its bell, but normally it is almost invisible to us. What does that mean?

Homework Statement Electrolysis of an aqueous solution of copper(II) nitrate was carried out using copper electrodes. The mass of the anode decreased by 1.28 g while that of the cathode increased by 1.18 g Assuming that the copper anode contains silver and gold impurities, which statement is...

I also like to ask, since no one comment about that, is water a ligand or aqua? I know that both refer to H2O, but if I want to mention a ligand, which one of them, aqua/aqua ligand/water/water ligand, is more appropriate?

Homework Statement From what I've read, [Cu(H2O)6]2+ when reacts with concentrated hydrochloric acid, the chloro ligand will displace the aqua ligand and form [CuCl4]2- Homework Equations [Cu(H2O)6]2+ + 4Cl- <--> [CuCl4]2- + 6H2O ( <---> means reversible reaction, I don't know how to type it...

Ohhh, I got it But what about the next question? I thought the more polarised a bond is, the stronger it is, so it's less reactive?

I don't understand

For acyl chloride the very electronegative oxygen atom attracts electrons of the carbon atom, thus greatly polarised the C-Cl bond. But won't it attract electrons of the Cl atom too? Then with the electrons drifting towards the C atom, it's partial positive charge should be reduced, but why is...