Answer:
a magnet that retains its magnetic properties in the absence of an inducing field or current
Answer:
C) A ratio based on the mass of a carbon-12 atom
Explanation:
For each element, there is a characteristic number of protons, this number represent a type of atom and its called the atomic number
On the other hand we have the number of neutrons, and for one element which difers only on the number of neutrons, we have different isotopes from one element.
Together, protons and neutrons define the mass number
One property linked with the mass number, is the atomic mass, which is formerly expressed as "uma" (atomic mass unit)
By definition, one atom of carbon-12 (with 6 neutrons) has an atomic mass of 12 umas
I believe the coma is formed from the dust and gas from a comet.
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