The relative mass of each element can be found from the periodic table (the larger number). For instance, P2O5, P = 31.0 O = 16.0, thus the formula mass (Mr) is 2(31) + 5(16) = 142 amu (atomic mass unit). I used a not really specific periodic table. Maybe your teacher is referring to open Schoology (a website where teacher can post files or announcements to students in his or her class). Sorry if i got something mistaken.
Answer:
Because water conducts electricity, so if an electrical current were to meet the water while you're in there taking a bath, you would essentially be surrounded by a huge conductor.
Answer: 175.35g
Explanation: A 3 M solution has 3 moles of solute per litre.
The mass of one mole of NaCl equals the MW of NaCl MW = 35.45 + 23 =58.45 g/mol
The mass of 3 moles is 58.45 g/mol ×3 mol=175.35 g NaCl or 200 g rounded to one sigfig.