For each set of molecular formulas and molar masses, determine the empirical formula and its mass. a) C6H6 78.11g / m * o * l * b ) C2H4Cl4O2201.85 g/mol c) CCl4 153.81 g/mol

Evaluate this exponential expression,8. (2 + 3)2 – 42

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?