Please help will mark brainlest!! *only right answers*

Word problems: you may need the following values:6.626E-34 and 2.998E8 I am using the standard calculator symbol for scientific notion. On your work please write it out correctly.

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?

The number at the end of an isotope’s name is the number.