Sodium hydroxide, naoh is a strong base that is used in industrial synthesis and process such as making paper. what is the mass 2.60x10^22 molecules of naoh(molar mass=40.0g/mol)? express the mass in grans to three significant figures

Avagadros number/ constant states that there are 6.022 x 10²³ units making up 1 mol of any substance. 
In NaOH - there are 6.022 x 10²³ NaOH molecules in 1 mol of NaOH
Mass of 1 mol of NaOH - 40 g
therefore 6.022 x 10²³ molecules weigh - 40 g
Then 2.60 x 10²² molecules - 40 x  2.60 x 10²² / (6.022 x 10²³ ) 
   mass is then - 1.73 g 

No table found. the question asks for covalent bond based on electronegativies