Answer:
True
Explanation:
This is because the statement above fits the definition of a positive economic statement. A Positive economic statement refers to objective statements that can be verified, tested , amended or discarded by consulting available evidence .The statement above can be tested objectively to establish its veracity.
His the answer I hope it helps
Answer : The standard enthalpy of formation of ethylene is, 52.4 kJ
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 equation, we get :
(1)
(2)
(3)
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 52.4 kJ
Answer:
Super-heavy elements like 114 usually only exist for fractions of a second. ... The physicists called these magic numbers the “island of stability”, because the elements with the numbers cluster together on the periodic table, flanked on all sides by ephemeral elements that dissipate in nanoseconds.