The mass number plays an important role for elements and their isotopes. Mass number comes from the addition of protons and neutrons (their weight). Isotopes are the elements, but with a different number of neutrons. So in turn, by subtracting the number of protons (atomic number) from the mass, you can find the number of neutrons.
Answer: Order of the elements from most reactive to least reactive is:
Mg > Zn > Fe > H > Cu
Explanation: Reactivity of the elements is the tendency of the elements to loose or gain electrons with ease.
As, all the given elements are metals, so the metals which will loose electrons easily will be more reactive. To study the reactivity of metals, we use reactivity series.
The metals which are more reactive are placed on the top of the reactivity series and which are less reactive are placed at the bottom.
Hence, the order of the elements from most reactive to least reactive is:
Mg > Zn > Fe > H > Cu
Reactivity series is attached below.
Starting in 1908, while a professor at the University of Chicago, Millikan worked on an oil-drop experiment in which he measured the charge on a single electron. J. J. Thomson had already discovered the charge-to-mass ratio of the electron.
Amino groups due to the chain can extend longer than the other
2 moles of Na3PO4 form from 6.0 mol NaOH. Details about stoichiometry can be found below.
<h3>How to calculate number of moles?</h3>
The number of moles of a substance can be calculated stoichiometrically as follows:
3NaOH + H3PO4 → 3H₂O + Na3PO4
According to this equation,
3 moles of NaOH produces 1 mole of Na3PO4
This means that 6 moles of NaOH will produce 6/3 = 2 moles of Na3PO4
Therefore, 2 moles of Na3PO4 form from 6.0 mol NaOH.
Learn more about stoichiometry at: brainly.com/question/9743981
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