What is the atomic number f plus the atomic number of na equals the atomic number of this element?

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

How do you lengthen a pattern piece? (family and consumer science, sewing)