Answer:
There was an electron transfer where the marble has lost the same amount of electrons (being positively charged) that the piece of silk has gained (being negatively charged).
Explanation:
As a result of this transfer of electrons and the charges induced in the objects they will attract.
When a body is endowed with electrical properties, that is, it acquires electrical charges, it is said to have been electrified.
Electrification is one of the phenomena that studies electrostatics.
To explain how static electricity originates, we must consider that matter is made of atoms, and atoms of charged particles, a nucleus surrounded by a cloud of electrons. Normally, matter is neutral (not electrified), it has the same number of positive and negative charges.
Some atoms are easier to lose their electrons than others. If a material tends to lose some of its electrons when it comes into contact with another, it is said to be more positive in the Triboelectric series. If a material tends to capture electrons when it comes into contact with another material, that material is more negative in the triboelectric series.
Answer:
The answer to your question is given below
Explanation:
1. C. 2NaCl + I2 —> 2NaI + Cl2 => C. Single displacement.
From the above equation, we can see that I2 replaces Cl in NaCl to produce NaI. This is simply called a single displacement reaction.
2. E. 2C4H10 + 13O2 —> 8CO2 + 10H2O => E. Combustion.
The above equation shows the burning of Hydrocarbon in the presence of O2. This is simply called Combustion as CO2 and H2O is produced.
3. D 2H2O —> 2H2 + O2 => D. Decomposition.
From the above equation, we can see that a single compound H2O produces two elements H2 and O2. This is simply called a decomposition reaction.
4. A. ZnS + 2HCl —> ZnCl2 + H2S => A. Double Decomposition.
From the above equation, we can see that Cl replaces S in ZnS to produce ZnCl2 and S replaces Cl in HCl to produce H2S. This is simply called double displacement reaction.
5. B. H2 + Br2 —> 2HBr => B. Synthesis.
From the above equation, we can see that two element H2 and Br2 combine to produce a single compound HBr. This is simply called a synthesis reaction.
Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of 
will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equations, we get :
(1) 
(2) 
(3) 
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole
