Answer:
Explanation:
There are some radioactive nuclides can be used to measure time on an archeological scale. One is the best example of this is radiocarbon dating. This process is based on the ratio of caebon-14 to carbon-12 in the atmosphere which is relatively constant.
The half time of C-14 5730 years
Carbon-14 is a radioactive nucleus. It has a half-life of 5730 years.
All living tissues like plants and animal absorbed carbon-12 along with carbon-14 with same ratio of caebon-14 to carbon-12 in the atmosphere.
Carbon-14 dating is based on the ratio of carbon-14 to carbon-12 in the atmosphere which is relatively constant
Answer:
Potassium permanganate.
Explanation:
Both substances are dyes, but the methylene blue has a bigger molecular mass (319.85 g/mol), that means that the particles are bigger in comparison with the potassium permanganate that has a molecular mass of 158.034 g/mol.
Since the molar mass is the half in the case of potassium permanganate, it can be considered that the particle size is the half in size. In the agar, a smaller particle will present less resistance to flow, that means that it going to move faster.
Answer:
C. Gas exchange occurs through the placenta.
Explanation:
The fetus is a developing baby in the womb or uterus. The fetus is incapable of performing certain life processes itself and hence, depends on the mother to do them. One of these processes is GAS EXCHANGE. Gas exchange occurs in the fetus via a structure called PLACENTA.
Placenta is a structure that forms in the uterus during pregnancy. It helps the developing fetus supply oxygen and nutrients from the mother and also remove wastes from the fetus back to the mother. The oxygen is taken into the fetus via the PLACENTA while the carbon dioxide (waste product of respiration) is removed via the PLACENTA. Hence, Gas exchange occurs through the placenta.
