Answer:
The u (amu is the old unit name) is 1/12 of the weight of an 12C atom. The way the u is chosen ensures that all core and atom masses are multiples of 1(±0.1) u.
Explanation:
Further explanation if needed...
Carbon 12 was chosen because the chemical atomic weights based on C12 are almost identical to the chemical atomic weights based on the natural mix of oxygen. Simply because the atomic mass is defined as 1/12 of the mass of 12C. Others isotopes of carbon (13C mostly, with an abundance of 1.1% approximately) account for an average atomic mass slightly above 12.
True
Explanation:
Harry Hess in 1961 resurrected Wegener's continental drift hypothesis and also he mantle convection idea of Arthur Holmes by postulating the theory of sea floor spreading.
- After Wegener's postulation of the continental drift hypothesis, not much was done.
- It was only around 1931 that Arthur Holmes came up with the idea of a convecting mantle.
- After the second world war passed, new instruments were used to investigate and map the ocean floor.
- Through this, Arthur Holmes came up with the idea of a spreading sea floor.
- This gave a full gleam picture to the idea of a moving earth and the more accepted terminology of "Plate tectonics " came to the fore.
Learn more:
Sea floor spreading brainly.com/question/9912731
Continental drift brainly.com/question/5002949
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