D. The number of electrons equals the atomic number for a neutral element. Each number after the letter refers to the number of electrons in that shell. So for D, 2+2+6+2+6+2 = 20 electrons, which is equal to the atomic number.
Explanation: Like flowing water, wind picks up and transports particles. Wind carries particles of different sizes in the same ways that water carries them (Figure below). Tiny particles, such as clay and silt, move by suspension. They hang in the air, sometimes for days.
