Answer:
The ancient Greeks believed that there were four elements that everything was made up of earth, water, air, and fire.
Los antiguos griegos creían que había cuatro elementos y que todo estaba compuesto de tierra, agua, aire y fuego.
Explanation:
Answer: By performing the flame test
Explanation:
The flame test can be performed by the teacher to visually identify the substance in the solution. The metals give a characteristic color on burning. The heat of the flame causes the excitation of the electrons present in the metal ions this leads to release of energy along with the emission of visible wavelength of light. This visible light can be observed by human eye. For example, the copper produces the blue color in flame, barium gives green flame, and sodium gives yellow flame.
5-Methyl-5-ethyldecane should be the answer .
When reversing a given reaction, we simply change the sign of the standard enthalpy change value. Therefore, the reaction will become:
H₂O → H₂ + 0.5O₂, ΔH = 286kJ
This is because if a certain amount of energy is released when a reaction occurs, the same amount of energy must be supplied for the reaction to occur in the reverse direction.
