Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.
Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴
From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So,
Core Electrons = Total Electrons - Valence Electrons
Core Electrons = 34 - 6
Core Electrons = 28
Result:
There are 28 core electrons in Selenium.
Based on the charge on the aluminium ion, 0.9 g of aluminium are deposited by 0.1 F of electricity.
<h3>What is electrolysis?</h3>
Electrolysis is the decomposition of a substance known as an electrolyte when electric current is passed through it.
The mass and hence moles an electrolyte deposited when current is passed through it depends on the charge on the ion.
Aluminium ion has a charge of +3 and requires 3F of electricity to deposit 1 mole or 27 g of aluminium
0.1 F will discharge = 0.1/3 × 27 g of aluminium
mass of aluminium deposited = 0.9 g of aluminium.
Therefore, 0.9 g of aluminium are deposited by 0.1 F of electricity.
Learn more about electrolysis at: brainly.com/question/26050361
Answer:
The three laws of Chemical Reaction are .The law of constant proportions. The law of multiple proportions. The law of reciprocal proportions.
A chemical compound is always found to be made up of the same elements combined together in the same fixed proportion by mass.
potassium and chlorine gas ---> chloride.
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Molarity of solution is mathematically expressed as,
M =

We know that volume = mass/density
Given: mass of solution = 100 g, Density = 1.34 g/ml
∴ volume = 100/1.34 = 88.49 ml = 0.08849 l
Also, we know that molecular weight of sucrose = 342.3 g/mol
∴M =

= 6.979 M
Thus, molarity of solution is 6.979 M
Answer:
see below
Explanation:
for A + 2B => Products ...
Rate Law => Rate =k[A][B]ˣ
As shown in expression, A & B are included, C is not.