Which expression can be used to calculate the ratio of the rate of effusion of gas A to the rate of effusion of gas B?

The square root of the molar mass of B ÷ the square root of the molar mass of A

The square root of the molar mass of A ÷ the square root of the molar mass of B

The molar mass of A ÷ the molar mass of B

The molar mass of B ÷ the molar mass of A

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?