I think the best one is B
Explanation:
⁶⁵₃₀Ca → ⁶⁵₂₉Sc + ⁿₓH
The reaction above is nuclear reaction.
In a nuclear reaction, the mass number and atomic number must be conserved.
The mass number is the superscript before the atom
Atomic number is the subscript before the atom
Conserving mass number:
65 = 65 + n
n = 0
conserving atomic number:
30 = 29 + x
x = 1
The unknown atom is a positron i.e a positively charged electron: ⁰₁e
⁶⁵₃₀Ca → ⁶⁵₂₉Sc + ⁰₁e
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Transmutation brainly.com/question/3433940
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Is this the full question?
<span>Heat that flows by conduction is the transfer of thermal energy between substances in contact. For this to happen, what must occur?
A) The two systems must be the same temperature.
B) The two systems must not be touching each another.
C) One system must have higher kinetic energy than the other system.
D) The thermal energy of one system must be the same as the thermal energy of the other system.</span>
<span>fossil fuels are mainly organic compounds.Combustion of fossil fuels also produces other air pollutants, such as nitrogen oxides, sulfur dioxide, volatile organic compounds and heavy metals.so,substances which contain sulphur cause to form harmful acids like sulphuric and sulphurus acids</span>
Halogens can be characterized as :
1) High Electronegativity
2) Low melting & boiling points
3) Forms Ionic compounds
4) Non-metallic in nature
Hope this helps!