How many valence electrons does a neutral atom of aluminum have?
a. 3
b. 10
c. 13
d. more information is needed to figure this out.

What is the amount of energy for a photon that has a 125 cm wavelength

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost

Did the detergents containing enzymes work better at removing stains than those containing no enzyme? why or why not?