Answer:
4.64E14
Explanation:
First convert 645 nm to m = 6.4500E-7m. The equation for finding v with these values is the speed of light/wavelength. so 2.998E8/6.4500E-7m.
so your v or frequency would equal 4.64E14
Fun fact you know this is visible light because the visible light range is within the E14 range.
Answer:
Two hundred million years ago, Antarctica was a lush, temperate rainforest home to crocodile-sized amphibians and rhinoceros-sized dinosaurs.
Explanation:
Animals:
1 ankylosaurs (the armored dinosaurs), mosasaurs and plesiosaurs (both marine reptilian groups).
2 Cry-oloph-os-auru-s was the ap-ex pre-da-tor of its region when it hunted in the lands of Jur-as-sic Period Antarctica.
3 plesiosaurs.
4 mosasaurs.
Plants:
1 palm trees.
2 ferns and Tanglefoot.
3 Evergreen trees
4 Glossopteris
Answer:
It basically messes up the results
Explanation:
Pen ink consists of resins, pigments and other colouring dyes dissolved in appropriate solvents like propylene glycol, propyl alcohol and some other ethers. If the ball point pen is used to mark on the chromatography paper then these pigments will also move along with the solvent and interfere with the spots of our analyte.
If you use a ball point pen when doing a chromatogram, then the ink would separate as it is a mixture and run down the paper.
Graphite, or pencil lead however, is not an organic material and therefore will not be affected by common organic solvents used for thin-layer chromatography. Pen ink on the other hand will be readily absorbed by the solvent and will move up the plate.
Physical properties are those which can be observed without any change in composition of the substance. Hence, a is the answer.
Answer:
The strength of a bond between two atoms increases as the number of electron pairs in the bond increases.
Explanation:
