Answer: 68
Explanation:
Isotopes of an element have same number of protons but different number of neutrons. Which means isotopes of an element have same atomic number but different mass number.
Atomic number is equal to the number of protons or the number of electrons for a neutral atom and is specific to a particular element.
Mass number is the sum of number of protons and the number of neutrons.
Given : atomic number of element Q = 68 = number of protons
Mass number of isotope Q-136 = 136
But as isotopes have same atomic number, the number of protons will be same and hence there are 68 protons are in a neutral atom of this isotope.
The percentage of Chromium in Chromium Oxide is calculated as follow,
Step 1: Calculate Molar mass of Cr₂O₃,
Cr = 51.99 u
O = 16 u
So,
2(51.99) + 3(16) = 103.98 + 48 = 151.98 u
Step 2: Secondly divide molar mass of only chromium with total mass of Cr₂O₃ and multiply with 100.
i.e.
=

× 100
=
68.41 %
So, the %age composition of chromium in chromium oxide is
68.41 %.
The rate of the reaction increases when a catalyst has been added to the reaction mixture by e) providing a new mechanism for the reaction to procced by
Catalyst, in chemistry, a substance that speeds up a reaction without itself being consumed. Enzymes are natural catalysts responsible for many important biochemical reactions.
Most solid catalysts are oxides, sulfides, halides of metals or metallic elements, and metalloid elements boron, aluminum and silicon. Gas and liquid catalysts are usually used in pure form or in combination with suitable carriers or solvents. Solid catalysts are usually dispersed in another material known as a catalyst support.
Learn more about the catalyst in
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Answer:
Valence electrons of selenium will be placed in s and p-orbitals.
Explanation:
Hope this helps.
Answer:
V CH3OH = 262.5 mL
Explanation:
- %v/v = (v compound / v sln)×100
∴ %v/v = 21.0 %
∴ v sln = 1.25 L
⇒ v compound = ?
⇒ 21.0 % = ( v compound / 1.25)×100
⇒ 0.21 = v compound / 1.25 L
⇒ (0.21)*(1.25 L) = v compound
⇒ v compound = 0.2625 L = 262.5 mL