Unburned hydrocarbon on reacting with oxygen undergoes combustion reaction. However, the activation energy of this reaction is significantly high. When a catalyst like Pd is added to the reaction system, it provides active sites for the reaction to occur. It acts are a heterogeneous catalyst. It is pertinent of note that catalyst is refereed as heterogeneous, when it exist in different phase as compared to reactant and products. In present case, reactants and products are in gas phase, while catalyst is in solid phase. Due to availability of larger surface area at active site of Pd, activation energy of reaction decreases and decrease in activation energy favors higher reaction rates.
Answer:
Scientists believe that comets are the debris left from the solar nebula which condensed to form the Sun and planets in our solar system. Most comets are thought to originate in a huge cloud called the Oort Cloud. ... Comets follow a regular orbit around the Sun.
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Explanation:
Answer:
m= 4,599.145 g
Explanation:
Let m = mass, d = density and V = volume of the osmium block.
m = d x V
m = 22.610 g/cm3 x (6.70 x 9.20 x 3.3) cm3
m = 4,599.145 g
Answer:
Option C.
Explanation:
The arrangement of electrons in their orbital follows certain rules.
The Hund's rule practically explained how electrons are distributed in their orbitals.
The Hund's rule states that electrons distributed among the orbitals of the same shell singly (without partner) before pairing occurs.
In the filling of these electrons in their orbitals, we fill in the electron without pairing first because electrons tends to repel each other before filling with the opposite spin as shown in the attached photo.