In a gasoline engine, the area in the cylinder head where the air-and-fuel mixture is burned is called the
a. combustion chamber.
b. intake valve.
c. cylinder.
d. piston.

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?

What shape would a molecule with two bound groups and two lone pairs have?

Which of these is not an example of chemical weathering? a. iron-rich mineral rusting b. feldspar turning into clay c. limestone reacting with acid d. granite breaking up into sand