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.
Answer:
First
divide each element by its Molecular Mass to get their respective moles
Then Divide through by the lowest of the moles
You'll have the ratio of Carbon Hydrogen and Oxygen to be
C2H3O
Given Molecular Mass=184.27
C2H3On=184.27
n(12x2 + 1x3 + 16) =184.27
Evaluating this... You'll have n=4.3
Pls check if you assigned the correct value to each element
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
Answer:
Where the products are H2O and Ba(NO3)2
Explanation:
A base, as, barium hydroxide (Ba(OH)2) reacts with an acid (HNO3), producing water (H2O), and the related salt (Ba(NO3)2) in a reaction called <em>neutralization reaction.</em>
The balanced reaction is:
Ba(OH)2 + 2 HNO3 → 2 H2O + Ba(NO3)2
<em>Where the products are H2O and Ba(NO3)2</em>
Answer:
6.72 g
Explanation:
Given data:
Mass of calcium chlorate = 13.8 g
Mass of oxygen produced = ?
Solution:
Chemical equation:
Ca(ClO₃)₂ → CaCl₂ + 3O₂
Number of moles of calcium chlorate:
Number of moles = mass / molar mass
Number of moles = 13.8 g/ 206.98 g/mol
Number of moles = 0.07 mol
Now we will compare the moles of oxygen and calcium chlorate.
Ca(ClO₃)₂ : O₂
1 : 3
0.07 : 3×0.07=0.21 mol
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.21 mol × 32 g/mol
Mass = 6.72 g
