Answer:
Electrons on the outermost shell of an atom. They are responsible for the chemical properties of an atom.
A thermochemical reaction is a chemical reaction with an additional information of the heat of reaction. For example, this is the thermochemical reaction for the combustion of hydrogen gas:
H₂ (g) + 1/2 O₂ (g) → H₂O (l) ΔH = -285.8 kJ
The coefficient 1/2 represents the number of moles of O₂ needed to combust 1 mole of H₂ gas in order to yield one mole of water.
To measure weight of a item
Answer:
Mendeleev had left the noble gases out of his periodic table.
Explanation:
Mendeleev's periodic table is pictured in the image attached to the question.
Mendeleev's table obviously lacked the noble gases. The reason for this grave omission is simple; the noble gases were not known as at the time when he formulated his periodic table. There weren't any known elements whose properties were similar to the properties of the noble gases. This would have lead him to suspect their existence.
This it true because in the triangle of the transformation from solid, liquid, and gas
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