I can save a variable M (actually a matrix) using

save M, "Test" or save M, "Test..xyz"

where .xyz can be any file extension except .m  This saves the variable in "Maple language format" and it can be restored using

read "Test" or read "Test.xyz".

But if I save with a .m extension

save M,"Test.m" then

read "Test.m" does not seem to restore the variable. What am I missing?

Secondly, is there a recommended file extension for a Maple language format file created with the save command?

I need a combobox with two columns but I don't think it is possible.  I want to display a list of acids with their names and dissociation constants.

I have a worksheet mode worksheet which I would like to continue developing as a document mode worksheet - they couldn't have chosen more confusing terminology if they had tried!

So, as the title says, can a worksheet mode worksheet be saved as or converted to a document mode worksheet?

I have checked the help and documentation and have googled but to no avail.  I am not very hopeful ...

And, if they are not inter-convertible, why refer to them both as worksheets and give them the same file extension

I have a fairly simple worksheet with a 56x2 matrix M1 which I am trying to export to Excel with the following 

ExcelTools:-Export( M1, "C:/Temp/M1.xlsx", 1, "B2")

This causes the following message to appear

After that the program is frozen and totally unresponsive.  The only way to proceed is end the task in Task Manager..

I am trying to upload the worksheet but am not sure if I have succeeded

Download Calculation_of_pH_from_known_values_of_Vb.mwCalculation_of_pH_from_known_values_of_Vb.mw

I have never use Maple before and have the following equation

c_a, c_b, K_a, K_b, K_w and V_a are either constants or pre-determined (V_a).  I know it should be easy to tabulate/calculate values of V_b for given values of [H⁺] (hydrogen ion concentration) but how easy would it be to determine values of [H⁺] for selected values of V_b?  Would it be easy to set up bearing in mind my lack of experience?