Answer:
38
Explanation:
Symbol: Sr
Atomic mass: 87.62 u
Electrons per shell: 2,8,18,8,2
Atomic number: 38
Electron configuration: [Kr] 5s2
Van der Waals radius: 255 pm
Valence electrons: two
Answer:
Law of Conservation of Energy
Explanation:
The reaction;
O(g) +O2(g)→O3(g), ΔH = sum of bond enthalpy of reactants-sum of food enthalpy of products.
ΔH = ( bond enthalpy of O(g)+bond enthalpy of O2 (g) - bond enthalpy of O3(g)
-107.2 kJ/mol = O+487.7kJ/mol =O+487.7 kJ/mol +487.7kJ/mol =594.9 kJ/mol
Bond enthalpy (BE) of O3(g) is equals to 2× bond enthalpy of O3(g) because, O3(g) has two types of bonds from its lewis structure (0-0=0).
∴2BE of O3(g) = 594.9kJ/mol
Average bond enthalpy = 594.9kJ/mol/2
=297.45kJ/mol
∴ Averange bond enthalpy of O3(g) is 297.45kJ/mol.
Input the atomic masses of Mg and P to give 134.84g/mol
Explanation:
The molar mass of a substance (atom or molecule or compound) is the mass in grams of one mole of the substance:
When dealing with an element the molar mass is the relative atomic mass expressed as g/mol.
For compounds, you add the atomic masses of the component atoms and you sum up.
You simply input the atomic mass of 3 atoms of Mg and 2 atoms of P
Atomic mass of Mg = 24.3g/mol
P = 30.97g/mole
Molar mass of Mg₃P₂ = 3(24.3) + 2(30.97) = 134.84g/mol
learn more:
Molar mass brainly.com/question/2861244
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