Select the statements that are true regarding open tubular and packed columns in gas chromatography. A. For similar analysis times, open tubular columns provide better resolution than packed columns.
B. Packed columns offer increased sensitivity to small sample sizes.
C. Packed columns have a greater sample capacity than open tubular columns.
D. Open tubular columns give better resolution but longer analysis separation times compared to packed columns.
E. Packed columns give broader peaks with longer retention times.

The image compares the arrangement of electrons in two different neutral atoms. a figure labeled atom q has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has six black spheres. to the left of this figure is another figure labeled atom p. atom p has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has seven black spheres. which of the following best explains the position of the two atoms in the periodic table? atom p has an estimated zeff of 7 and is therefore to the left of atom q, which has a zeff of 6. atom p has an estimated zeff of 7 and is therefore to the right of atom q, which has a zeff of 6. atom p has an estimated zeff of 5 and is therefore below atom q, which has a zeff of 4. atom p has an estimated zeff of 5 and is therefore above atom q, which has a zeff of 4.