How many phosphorus atoms are there in 2.57g of this element

how many days are there in this the atoms of given element 翻译:How many Mondays are there in this month? How many letters(字母) are there in this face? how many horses'feet are there in this picture是什么意思 how many day are there in this month How many ____ (read ) rooms are there in this building how many ____ (store) are there in this city How many people are in this family How many people are there How many types of universities are there in Britain? How many kinds of animals are there in the passage? How many kinds of animals are there in the w