CREATE TABLE table_40355 ("number" FLOAT, "symbol" TEXT, "name" TEXT, "empirical \\u2020" TEXT, "Calculated" TEXT, "van der Waals" TEXT, "Covalent  ( single bond ) " TEXT, "Covalent  ( triple bond ) " TEXT)

What is the covalent (single bond) value of sodium?
SELECT "Covalent (single bond)" FROM table_40355 WHERE "name" = 'sodium'
SELECT "Covalent (single bond)" FROM "table_40355" WHERE "name" = 'sodium'