The correct coefficients needed to balance the following reaction are: ___ PbI2 + ___ ZnS → ___ PbS + ___ZnI2
a) 1, 2, 2, 1
b) 1, 1, 1, 1
c) 1, 1, 2, 2
d) 2, 1, 1, 2

How do scientists think that gravity affected the formation of our solar system?

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?