What is the empirical formula for a compound that containts 0.0130 mol carbon, 0.0390 mol hydrogen, and 0.0065 mol oxygen

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

In 2002, the rare earth elements mine in mountain pass, california was closed because

Abeaker with 2.00×102 ml of an acetic acid buffer with a ph of 5.000 is sitting on a benchtop. the total molarity of acid and conjugate base in this buffer is 0.100 m. a student adds 4.70 ml of a 0.360 m hcl solution to the beaker. how much will the ph change? the pka of acetic acid is 4.740.