Answer:
B
Explanation:
An exothermic reaction is one in which heat is liberated to the surrounding by a reaction.In this case,the enthalpy of the product is less than that of the reactant and such a reaction has a negative enthalpy (ΔH).
Answer:
Pure substance B) Consists of a single element or type of compound.
Homogeneous A) Mixture that has its different components mixed evenly within the substance.
Heterogeneous D) Mixture that has its different components mixed unevenly within the substance.
Solution C) Liquid homogeneous mixture in which the solute is distributed evenly within the solvent.
Explanation:
Pure substances are a form of matter with definite constant composition and distinct properties. They consist of a single element or type of compound, as can be seen in its formula. Na, O₂, NaCl and H₂O are examples of pure substances.
When 2 or more pure substances are mixed together they form a mixture. If the mixture has its different components mixed <u>evenly</u> within the substance it is a homogeneous mixture. Whereas if the mixture has its different components mixed <u>unevenly</u> within the substance it is a heterogeneous mixture. The different parts observable in a heterogeneous mixture are known as phases.
In liquid homogeneous mixtures, we can recognize one or more substances that are in lower proportions (solutes) and one substance that is in greater proportion (solvent). This kind of mixture is known as a solution.
Tc-99m<span> is a </span>metastable isomer<span> of </span>Tc-99. It finds widespread applications in <span>medical diagnostic procedures.
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Tc-99 is also a radioactive element. It's half-life is 2,11,000 years. Upon radioactive decay, it emits beta particles and gets converted into stable compound Ruthenium-99
This process of radioactive decay is shown below.
99 43Tc → 99 44Ru + 0 -1e
(stable) (β particle)
<span><span>Mn<span>O<span>2<span>(s)</span></span></span>+<span>H<span>2<span>(g)</span></span></span>→Mn<span>O<span>(s)</span></span>+<span>H2</span><span>O<span>(g)</span></span></span></span>
<span>Cost and availability of fuel is a considerable factor when dealing with nuclear power. Fission requires an element that can be easily split in a particle accelerator, such as uranium or plutonium. Fusion, on the other hand, uses isotopes of hydrogen atoms, specifically deuterium and tritium, that can be obtained from ordinary water</span>
