A has distinct properties and composition that never vary

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

Based on the formulas, select the compounds below that are covalent: kbr sif4 al2o3 co2 naco3 s7o2 pcl3 fe3n2 h2o s2f10

Why is any chemical reaction always balanced? give reasons and explain the easiest way to solve the balancing problems in chemical equations with stoichiometric coefficients upto 20 as hit and trial doesn't always work. give full reasoning