Help, please! Which property of a substance can be determined using a pH indicator ?

Density
Acidity
Electrical Conductivity
Thermal Conductivity
Boiling Point

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

What produces wave a)sound b) heats c)transfer of energy d)vibrations

Connect the whole numbers on the periodic table to indicate what they represent?