The answer is 64.907 amu.
The atomic mass of an element is the average of the atomic masses of its isotopes. The relative abundance of isotopes must be taken into consideration, therefore:
atomic mass of copper = atomic mass of isotope 1 * abundance 1 + atomic mass of isotope 2 * abundance 2
We know:
atomic mass of copper = 63.546 amu
The atomic mass of isotope 1 is: 62.939 amu
The abundance of isotope 1 is: 69.17% = 0.6917
The atomic mass of isotope 1 is: x
The abundance of isotope 2: 100% - 69.17% = 30.83% = 0.3083
Thus:
63.546 amu = 62.939 amu * 0.6917 + x * 0.3083
63.546 <span>amu = 43.535 amu + 0.3083x
</span>⇒ 63.546 amu - 43.535 amu = 0.3083x
⇒ 20.011 amu = 0.3083x
⇒ x = 20.011 amu ÷ 0.3083 = 64.907 amu
Answer:
in disodium phosphate = 4 oxygen atoms
in phosphoric acid = 1 oxygen atom
B. Fluorine (F) is the right answer
Answer:
B I believe im sorry if it's not right
B. the periodic law
Explanation:
The periodic law was not explained by the Dalton's atomic theory.
The periodic law was first postulated by Dimitry Mendeleef and Lothar Meyer around 1869 where they independently arrived at the periodic table or chart.
- The table was based on the periodic law which states that "chemical properties of elements are a periodic function of their atomic weights".
- The modern periodic law was restated by Henry Moseley in the early 1900s. He changed the basis of the law to atomic number.
- The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".
The laws of conservation of mass, multiple proportions and definite proportions are all explained by the Dalton's atomic theory.
learn more:
Dalton's model of the atom brainly.com/question/1979129
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