Which of the following is an observation and not an inference?
a.
a cup with steam coming from it will be hot to the touch.
b.
dark clouds in the sky will mean rain later in the afternoon.
c.
bubbles form when two chemicals are mixed together.
d.
a plastic bag moving along the ground is being pushed by the wind.

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?

The diagrams to the right show the distribution and arrangement of gas particles in two different containers. according to kinetic-molecular theory, which of the following statements is true? check all that apply. if the temperatures of both containers are equal, container a has greater pressure than container b. if the volume of container a decreased, its pressure would decrease. if the pressure in both containers is equal, container a has a lower temperature than container b.

Scientists are often interested in knowing the molar heat of combustion – the heat released during the combustion of one mole of a substance. use the periodic table to find molar masses. how many moles of ethanol are present in the sample?