Answer:-
A. A water molecule
Explanation:-
A molecule is the smallest particle of a compound that retains all it's chemical properties.
Here H2O is a compound. So the smallest particle that will retain all the chemical properties and still remain water is water molecule.
Atoms Hydrogen and Oxygen both have different chemical properties from water H2O and are thus different.
Hydrogen peroxide is different molecule from water. So it is also not water.
Answer:
No metals. Right side.
Explanation:
On the right. Non metallic elements
Answer:
-105 kJ
Explanation:
The enthalpy change of a reaction is the sum of the energy of the bonds of the reactants and the products. The bonds at the reactants are being broken, so it's an endothermic reaction, so the bond energy must be positive.
The bonds at the products are being formed, so the process is exothermic, and the bond energy must be negative. There are being broken 1 N≡N bond and 3 H-H bonds, and are being formed 6 N-H bonds:
Reactants: 945 + 3*432 = 2241 kJ
Products: 6*(-391) = -2346 kJ
ΔH = 2241 - 2346
ΔH = -105 kJ
Significant figures are all the digits excluding leading zeros for small decimals and zeros at the end of an integer.
45.030 has 5 significant figures because the zero at the end is after the decimal point. This means that the number was measured with 3 decimal places of precision. If the last zero was not significant, the number would be written 45.03.
On the other hand, 45030 only has 4 significant figures. Hope this helps!
Answer:
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