Two moles of lithium has a mass of 13.88g. true or false

That would be false your welcome

From the periodic table:

the mass of lithium = 6.941 grams

Since lithium is monoatomic, therefore, the molar mass of lithium = 6.941 grams

Now, we need to calculate the mass of two moles of lithium:

mass of two moles of lithium = 2 * 6.941 = 13.882 grams

Based on the above calculations, the answer is:

True