Building a tower out of magnetic blocks and water vapor condensing on a bathroom mirror are only physical changes.
A physical change is easily reversible. It does not involve a change in the composition of a substance.
A tower built out of magnetic blocks can easily be pulled apart and water that condensed on a bathroom mirror can easily change back to vapour by heating.
All these are possible because the both processes are only physical changes.
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Covalent bonding because I remember from school
Answer:
C). Electronegativity.
Explanation:
'Electronegativity' is described as the tendency or a measure of the ability of an atom or molecule to attract electrons that leads to the formation of chemical bonds. It is denoted by 'χ', a Greek letter. The elements like Fluorine having a very high rate of electronegativity, its atom would attract the electrons more strongly while the elements with lesser electronegativity like Cesium would possess a lesser tendency to attract electrons towards it in order to form a bond. Thus, <u>option C</u> is the correct answer.
Answer:
what I'm not really understand this question
Answer:
This is an exothermic reaction
q = 563 kJ
Explanation:
Step 1: The balanced thermochemical equation
H2CO(g) + O2(g) → CO2(g) + H2O(l) ΔH = -563 kJ
This is a combustion, this means there will be released heat. This means it's an exothermic reaction.
The energy involved, will be released (that's why ΔH is negative)
q has the same value as ΔH (but positive)
q = 563 kJ
