Secretary of State John Hay sent his Open Door Notes (1899-1900) to world powers to protect United States trading interests in China. The correct option among all the options that are given in the question is option "3". These notes were mainly in regards to providing equal opportunity for trades in China and also respecting China's sovereignty, territorial integrity and administration. The principles of operating in China was the same for the British as well as for the United States, but John Hay was the first person to give it a written form. After this the official policy of the United States was based on the written document during the first half of the 20th century.
Answer: d) -705.55 kJ
Explanation:
Heat of reaction is the change of enthalpy during a chemical reaction with all substances in their standard states.
Reversing the reaction, changes the sign of 
On multiplying the reaction by 
, enthalpy gets half:
Thus the enthalpy change for the given reaction is -705.55kJ
Scientists use scientific notation to communicate extremely small measurements. Hence, option A is correct.
<h3>What scientific notation?</h3>
Scientific notation is a way of writing very large or very small numbers.
Scientists use scientific notation to represent very small or very large numbers because this notation increases the
- accuracy of measured quantities.
- convenience in using the numbers.
- the number of significant figures.
- precision of measurements.
Hence, option A is correct.
Learn more about the scientific notation here:
brainly.com/question/18073768
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the answer is c
Explanation:
because c has all elements mixed together
